Physics

Static friction is the force that prevents an object from moving when a force is applied to it. It is often greater than kinetic friction, which is the force that opposes the motion of an object that is already moving. The reason for this is that static friction is caused by the interlocking of irregularities on the surfaces of two objects in contact. These irregularities need to be overcome in order for the object to start moving. Once the object is in motion, the irregularities are no longer interlocked, resulting in a lower frictional force. In summary, static friction is greater than kinetic friction because it requires more force to overcome the initial resistance to motion.

Key Takeaways

Static Friction	Kinetic Friction
Higher	Lower

Understanding Friction

Friction is a fundamental concept in physics that plays a crucial role in our everyday lives. It is the force that opposes the relative motion or tendency of motion between two surfaces in contact. Friction is present in various forms and has both practical and scientific significance.

Definition and Importance

Friction can be defined as the resistance encountered when two objects move or try to move against each other. It is a result of the interaction between the surface irregularities of the objects in contact. This interaction creates a force known as the frictional force, which acts parallel to the surfaces and opposes the motion.

The importance of friction lies in its ability to provide stability and control. Without friction, it would be challenging to walk, drive a car, or even hold objects. Friction allows us to grip surfaces, prevents objects from sliding uncontrollably, and enables us to perform various tasks in our daily lives.

Types of Friction

Friction can be classified into different types based on the conditions under which it occurs. The two main types of friction are static friction and kinetic friction.

1. Static Friction: Static friction is the resistance encountered when two objects are at rest and attempting to move. It prevents the objects from sliding against each other until a certain force is applied to overcome it. The force required to initiate motion is known as the force of static friction. This type of friction is influenced by factors such as the nature of the surfaces in contact, the force pressing the surfaces together, and the surface roughness.

2. Kinetic Friction: Kinetic friction, also known as sliding friction, occurs when two objects are in motion relative to each other. It opposes the motion and acts in the direction opposite to the velocity of the objects. The force of kinetic friction is generally less than the force of static friction. Factors such as the nature of the surfaces, the force pressing the surfaces together, and the presence of lubricants affect the magnitude of kinetic friction.

Understanding the physics of friction is essential for comprehending the laws of motion and the behavior of objects in motion. The coefficient of friction, which quantifies the frictional resistance between two surfaces, is a key parameter in analyzing frictional forces. It represents the ratio of the force of friction to the normal force pressing the surfaces together.

Friction is not limited to solid surfaces but also occurs in fluids and gases. In everyday life, we encounter various examples of friction, such as the resistance experienced when walking on a rough surface, the grip between car tires and the road, or the rolling of a ball on the ground.

In summary, friction is a fundamental force that affects the motion and stability of objects. By understanding the different types of friction and the factors that influence it, we can better comprehend the physics of movement and its applications in our daily lives.

Deep Dive into Static Friction

Static friction is a fundamental concept in physics that plays a crucial role in our everyday lives. It is the force that prevents an object from moving when a force is applied to it. In this deep dive, we will explore the definition and explanation of static friction, the factors that affect it, and its significance in our daily lives.

Definition and Explanation

Static friction is the force that acts between two surfaces in contact with each other, preventing relative motion between them. It occurs when an object is at rest and a force is applied to it, but the object does not move. This force arises due to the interlocking of microscopic irregularities on the surfaces, creating resistance to motion.

To understand static friction better, it is essential to differentiate it from kinetic friction. While static friction prevents motion, kinetic friction comes into play when the object is already in motion. The force of static friction is generally greater than the force of kinetic friction, as it requires more energy to overcome the initial resistance and set an object in motion.

The magnitude of static friction depends on the coefficient of friction, which is a property of the materials in contact. The coefficient of friction is a dimensionless value that represents the ratio of the force of friction to the normal force between the surfaces. It varies depending on the nature of the materials and their surface roughness.

Factors Affecting Static Friction

Several factors influence the magnitude of static friction between two surfaces. These factors include:

1. Surface Roughness: The rougher the surfaces, the greater the interlocking of irregularities, resulting in higher static friction.
2. Normal Force: The force exerted perpendicular to the surfaces affects the magnitude of static friction. As the normal force increases, so does the static friction.
3. Nature of Materials: Different materials have different coefficients of friction. For example, rubber on concrete has a higher coefficient of friction than ice on ice.
4. Surface Area: The larger the contact area between the surfaces, the greater the static friction.

Understanding these factors is crucial in various fields, such as engineering, where frictional resistance plays a significant role in designing structures and machinery. By manipulating these factors, engineers can optimize the performance and efficiency of mechanical systems.

Role of Static Friction in Daily Life

Static friction is present in numerous aspects of our daily lives, often without us even realizing it. Here are a few examples:

1. Walking: When we walk, static friction between the soles of our shoes and the ground prevents us from slipping. The coefficient of friction between the shoe material and the walking surface determines the grip and stability.
2. Driving: The static friction between the tires of a vehicle and the road surface allows us to accelerate, decelerate, and make turns safely. The coefficient of friction between the tire rubber and the road plays a crucial role in maintaining control.
3. Opening Jars: When we struggle to open a tightly sealed jar, it is the static friction between the lid and the jar’s rim that makes it difficult. Applying more force increases the static friction until it is overcome, allowing the lid to twist open.
4. Writing: The friction between the pen or pencil and the paper enables us to write. Without static friction, the writing instrument would slide uncontrollably, making it impossible to create legible words.

These examples illustrate how static friction is an integral part of our daily activities. By understanding the physics of friction and its role in our lives, we can appreciate the importance of this force and its impact on our interactions with the physical world.

In conclusion, static friction is a fascinating concept that governs the resistance to motion between two surfaces in contact. By exploring its definition, factors affecting it, and its role in our daily lives, we gain a deeper understanding of the physics of movement and the significance of friction in our everyday experiences.

Deep Dive into Kinetic Friction

Friction is a fundamental concept in physics that plays a crucial role in our everyday lives. It is the force that opposes the motion of an object when it comes into contact with another surface. In this deep dive, we will explore the fascinating world of kinetic friction and its various aspects.

Definition and Explanation

Kinetic friction, also known as sliding friction, is the force that acts between two surfaces in relative motion. It comes into play when an object slides or moves across another surface. Unlike static friction, which prevents the object from moving initially, kinetic friction acts to resist the motion of the object.

The magnitude of kinetic friction depends on several factors, including the nature of the surfaces in contact, the force pressing the surfaces together, and the roughness of the surfaces. The coefficient of friction, denoted as μ, is a dimensionless quantity that represents the ratio of the force of friction to the normal force between the surfaces.

To better understand the concept, let’s compare kinetic friction with static friction. While static friction keeps an object at rest, kinetic friction comes into play once the object is in motion. The force of kinetic friction is generally lower than static friction, as it only needs to counteract the motion rather than prevent it entirely.

Factors Affecting Kinetic Friction

Several factors influence the magnitude of kinetic friction between two surfaces. These factors include:

1. Surface Roughness: The rougher the surfaces in contact, the greater the frictional force. Irregularities and bumps on the surfaces create more points of contact, leading to increased friction.

2. Normal Force: The force pressing the surfaces together, known as the normal force, affects the magnitude of kinetic friction. As the normal force increases, so does the frictional force.

3. Nature of Surfaces: Different materials have varying coefficients of friction. For example, rubber on concrete exhibits higher friction than ice on ice.

4. Sliding Speed: The speed at which the object slides across the surface can also influence kinetic friction. In some cases, the frictional force may increase with higher sliding speeds.

Role of Kinetic Friction in Daily Life

Kinetic friction plays a significant role in our daily lives, often without us even realizing it. Here are a few examples:

1. Walking: When we walk, the friction between our shoes and the ground allows us to move forward. Without kinetic friction, we would slip and struggle to maintain our balance.

2. Braking: The friction between the brake pads and the wheels of a vehicle enables us to slow down or come to a stop. Kinetic friction converts the kinetic energy of the moving vehicle into heat, helping us control our speed.

3. Writing: The friction between the pen or pencil and the paper allows us to create legible marks. Without kinetic friction, the writing instrument would simply slide across the paper without leaving any trace.

4. Sports: Kinetic friction is essential in various sports, such as soccer, where players rely on the friction between their shoes and the ground to change direction, stop, or accelerate.

Understanding the physics of friction, particularly kinetic friction, helps us comprehend the principles behind motion and resistance. By considering factors like surface roughness, normal force, and the nature of surfaces, we can better predict and manipulate the frictional forces in our daily lives.

So, the next time you walk, drive, or engage in any activity involving motion, take a moment to appreciate the role of kinetic friction and its impact on our everyday experiences.

Comparison between Static and Kinetic Friction

Friction is a force that opposes the relative motion between two surfaces in contact. It plays a crucial role in our everyday lives, affecting how objects move and interact with each other. When it comes to friction, there are two main types to consider: static friction and kinetic friction. Let’s explore the similarities and differences between these two types and delve into some practical examples.

Similarities and Differences

Both static and kinetic friction are forms of frictional forces that act between two surfaces in contact. However, they differ in their behavior and characteristics.

Static Friction:

Static friction is the force that prevents an object from moving when an external force is applied to it. It acts in the opposite direction to the applied force, effectively keeping the object at rest. The magnitude of static friction can vary depending on the force applied, but it always matches the applied force until a certain threshold is reached.

Kinetic Friction:

Kinetic friction, on the other hand, is the force that opposes the motion of an object that is already in motion. It acts in the direction opposite to the object’s velocity, slowing it down. Unlike static friction, the magnitude of kinetic friction remains relatively constant once the object is in motion.

Static Friction	Kinetic Friction
Acts on stationary objects	Acts on moving objects
Increases with the applied force until a threshold is reached	Remains relatively constant
Can be greater than kinetic friction	Is generally less than static friction

Practical Examples

To better understand the concepts of static and kinetic friction, let’s consider some practical examples:

1. Pushing a Heavy Box: Imagine you’re trying to push a heavy box across the floor. Initially, the box may not move due to static friction. As you apply more force, the static friction gradually increases until it reaches its maximum value, allowing the box to start moving. Once the box is in motion, kinetic friction comes into play, opposing its movement and making it harder to accelerate or maintain a constant speed.

2. Sliding a Book on a Table: When you slide a book across a table, static friction prevents the book from sliding off the table. As you increase the force, the static friction also increases until it reaches a point where the book starts sliding. Once the book is in motion, kinetic friction acts to slow down its movement, requiring more force to keep it sliding at a constant speed.

3. Car Braking: When you apply the brakes in a car, the brake pads exert a force on the rotating wheels. Initially, static friction prevents the wheels from locking up, allowing the car to slow down gradually. Once the wheels start rotating slower, kinetic friction takes over, further reducing the car’s speed until it comes to a stop.

In all these examples, the interplay between static and kinetic friction is evident. Understanding the differences between these two types of friction is crucial for predicting and controlling the motion of objects in various situations.

So, whether you’re pushing a heavy object, sliding something across a surface, or braking a vehicle, the physics of friction, both static and kinetic, are at play, influencing the motion and resistance you experience in your everyday life.

Why is Static Friction Greater than Kinetic Friction?

Scientific Explanation

When it comes to the physics of friction, understanding the difference between static and kinetic friction is crucial. Static friction refers to the force that prevents an object from moving when a force is applied to it. On the other hand, kinetic friction is the force that opposes the motion of an object already in motion. The question arises, why is static friction greater than kinetic friction?

To delve into the scientific explanation, we need to consider the role of the coefficient of friction. The coefficient of friction is a value that represents the interaction between two surfaces in contact. It determines the amount of frictional force between the surfaces. In the case of static friction, the coefficient of friction is typically higher than that of kinetic friction.

Role of Coefficient of Friction

The coefficient of friction plays a significant role in determining the magnitude of static and kinetic friction. It depends on various factors, including the nature of the surfaces in contact, surface roughness, and the presence of any lubricants. The coefficient of friction is generally higher for static friction because it takes more force to overcome the initial resistance and set an object in motion.

To better understand this concept, let’s consider an example. Imagine trying to push a heavy box across a rough floor. Initially, the box remains stationary due to the static friction between the box and the floor. The coefficient of static friction is higher because it requires a greater force to overcome the resistance and initiate movement. Once the box starts moving, the friction transitions to kinetic friction, which has a lower coefficient of friction.

Simple Explanation for Better Understanding

To put it simply, static friction is greater than kinetic friction because it takes more force to start an object’s motion than to keep it in motion. When an object is at rest, the surfaces in contact are interlocked at a microscopic level, creating a stronger bond. This bond needs to be broken by applying a force greater than the static friction to initiate motion.

Once the object is in motion, the surfaces slide over each other, resulting in a lower frictional force known as kinetic friction. The kinetic friction is generally lower because the surfaces are already in motion and experience less resistance compared to the initial static friction.

In everyday life, we encounter examples of static and kinetic friction. For instance, when you try to push a heavy piece of furniture, you may notice that it requires more effort to get it moving initially. Once it starts sliding, the force required to keep it in motion decreases. This phenomenon is a result of the difference between static and kinetic friction.

Understanding the concept of static friction being greater than kinetic friction is essential in various fields, including engineering, physics, and everyday life. By comprehending the factors affecting friction and the role of the coefficient of friction, we can better analyze and predict the behavior of objects in motion, ensuring efficient designs and smoother operations.

Is Static Friction Always Greater than Kinetic?

Friction is a fundamental concept in physics that plays a crucial role in our everyday lives. It is the force that opposes the relative motion between two surfaces in contact. When we think about friction, we often associate it with the idea that static friction is always greater than kinetic friction. However, is this always the case? Let’s explore the possibility of kinetic friction being greater and examine the conditions and scenarios where this might occur.

Exploring the Possibility of Kinetic Friction being Greater

In most cases, static friction is indeed greater than kinetic friction. Static friction refers to the force that prevents an object from moving when an external force is applied to it. On the other hand, kinetic friction is the force that opposes the motion of an object that is already in motion. The difference between the two lies in the nature of the surfaces in contact and the forces acting upon them.

To understand why static friction is usually greater, we need to consider the factors that affect frictional force. The coefficient of friction, which depends on the nature of the surfaces in contact, plays a significant role. The rougher the surfaces, the higher the coefficient of friction, and thus, the greater the frictional force. Additionally, the normal force, which is the force exerted by a surface perpendicular to the object, also influences the frictional force.

Conditions and Scenarios

While static friction is generally greater than kinetic friction, there are certain conditions and scenarios where the opposite can occur. Let’s take a closer look at these situations:

1. Surface Roughness: If the surfaces in contact have different roughness characteristics, it is possible for kinetic friction to be greater. For example, if a rough surface is sliding against a smoother surface, the roughness of the sliding surface can increase the frictional resistance, resulting in higher kinetic friction.

2. Motion Resistance: In some cases, the motion of an object can create additional resistance that increases the kinetic friction. This can happen when there are external forces, such as air resistance or fluid resistance, acting against the motion of the object. These additional resistive forces can contribute to a higher overall kinetic friction.

3. Physics of Movement: The physics of movement can also influence the relationship between static and kinetic friction. For instance, in the case of rolling friction, where an object rolls without sliding, the kinetic friction can be lower than static friction. This is because rolling motion involves less surface contact and deformation compared to sliding motion.

It is important to note that while there are scenarios where kinetic friction can be greater than static friction, these situations are relatively rare compared to the general rule that static friction is greater. Understanding the physics of friction and the factors that influence it can help us comprehend the complexities of friction in everyday life.

In conclusion, while static friction is typically greater than kinetic friction, there are conditions and scenarios where the opposite can occur. Factors such as surface roughness, motion resistance, and the physics of movement can influence the relationship between static and kinetic friction. By exploring these possibilities, we gain a deeper understanding of the fascinating world of friction and its impact on our daily experiences.

What Happens When Static Friction is Greater than Kinetic Friction?

When the static friction between two surfaces is greater than the kinetic friction, it means that it takes more force to initiate motion than to keep the objects in motion. This phenomenon has several implications on the motion of objects and can be observed in various real-life examples and applications.

Impact on Motion

When static friction is greater than kinetic friction, it means that there is a higher resistance to overcome when trying to set an object in motion. This is because static friction is the force that prevents two surfaces from sliding past each other when they are at rest. It acts in the opposite direction to the applied force, making it harder to initiate motion.

Once the object starts moving, the static friction transitions into kinetic friction. Kinetic friction is the force that opposes the relative motion between two surfaces in contact. It is generally lower than static friction, allowing the object to move more easily once it is in motion.

The difference between static and kinetic friction can be understood through the concept of the coefficient of friction. The coefficient of friction is a value that represents the frictional force between two surfaces. It is different for static and kinetic friction, indicating the varying levels of resistance.

Real-life Examples and Applications

Understanding the difference between static and kinetic friction is crucial in various real-life scenarios. Here are some examples and applications that demonstrate the impact of static friction being greater than kinetic friction:

1. Starting a Car: When a car is at rest, the static friction between the tires and the road surface is greater. This allows the car to remain stationary even when the engine is running. Once the driver applies enough force to overcome the static friction, the car starts moving, and the friction transitions to kinetic friction.

2. Pushing Objects: When pushing a heavy object, such as a bookshelf, the initial force required to overcome the static friction can be higher. Once the object starts moving, the kinetic friction reduces, making it easier to push the object.

3. Walking: The static friction between our shoes and the ground is essential for maintaining balance and preventing slipping. When we take a step, the static friction helps us push off the ground and propel ourselves forward. The transition to kinetic friction occurs when our foot slides during the walking motion.

4. Braking in Vehicles: When a vehicle brakes, the friction between the brake pads and the wheels is crucial for slowing down or stopping the vehicle. The static friction initially resists the motion of the wheels, allowing the brakes to engage. Once the wheels start moving slower, the friction transitions to kinetic friction, aiding in the braking process.

In conclusion, when static friction is greater than kinetic friction, it requires more force to initiate motion than to maintain it. This phenomenon has significant implications on the motion of objects in various real-life scenarios. Understanding the physics of friction and its impact on motion can help us comprehend the factors affecting frictional resistance and the physics of movement in our everyday lives.

Frequently Asked Questions

Addressing Common Queries

Here are some common questions about the physics of friction and their answers:

1. What is the physics of friction?
   The physics of friction deals with the study of the forces that resist the relative motion of objects in contact. It involves understanding concepts such as static and kinetic friction, frictional force, and the factors that affect friction.

2. What is the difference between static and kinetic friction?
   Static friction refers to the force that prevents an object from moving when a force is applied to it. On the other hand, kinetic friction is the force that opposes the motion of an object that is already in motion.

3. What is the frictional force?
   Frictional force is the force that acts between two surfaces in contact and opposes their relative motion. It arises due to the irregularities in the surfaces and the interlocking of their microscopic features.

4. What is the coefficient of friction?
   The coefficient of friction is a dimensionless quantity that represents the ratio of the frictional force between two surfaces to the normal force pressing them together. It varies depending on the nature of the surfaces in contact.

5. How do the laws of motion relate to friction?
   Friction is governed by Newton’s laws of motion. The first law states that an object at rest will remain at rest unless acted upon by an external force. The second law relates the force of friction to the mass and acceleration of an object. The third law states that for every action, there is an equal and opposite reaction.

Clarifying Misconceptions

Let’s address some misconceptions about friction:

1. Is friction always caused by surface roughness?
   While surface roughness can contribute to friction, it is not the only factor. Friction can also arise from adhesion between surfaces, intermolecular forces, and other factors.

2. Is sliding friction the same as rolling friction?
   No, sliding friction and rolling friction are different. Sliding friction occurs when two surfaces slide against each other, while rolling friction occurs when an object rolls over a surface.

3. Is friction only present when objects are in motion?
   No, friction can exist even when objects are at rest. This is known as static friction. It prevents objects from moving until a force is applied that overcomes the static frictional force.

4. What is the definition of static friction and kinetic friction?
   Static friction refers to the frictional force that prevents an object from moving, while kinetic friction is the force that opposes the motion of an object that is already in motion.

5. Does frictional resistance depend on the weight of an object?
   Frictional resistance depends on the normal force between two surfaces, which is influenced by the weight of an object. However, the coefficient of friction and the nature of the surfaces also play a significant role.

Remember, understanding friction is crucial as it plays a vital role in our everyday lives. From walking to driving, friction affects how objects move and interact with each other.

Conclusion

In conclusion, static friction is greater than kinetic friction due to the interlocking of microscopic irregularities on the surfaces of two objects in contact. When an object is at rest, the irregularities have more time to settle into each other, creating a stronger bond and increasing the force required to overcome the static friction. Once the object starts moving, the irregularities slide past each other more easily, resulting in a decrease in frictional force. This phenomenon explains why it is generally more difficult to initiate motion between two stationary objects than to maintain motion once it has started. Understanding the difference between static and kinetic friction is crucial in various fields, such as engineering, physics, and everyday life.

Why is static friction greater than kinetic friction? How does this relate to understanding different types of dry friction?

The concept of static friction being greater than kinetic friction is explored in the article “Why Static Friction is Greater than Kinetic“. This article discusses the reasons behind the difference in magnitudes between these two types of friction. To further understand this topic, it is important to have a comprehensive knowledge of dry friction and its various types. By delving into the article “Understanding Different Types of Dry Friction“, one can gain insights into the various categories of dry friction and their significance in different scenarios. Understanding different types of dry friction helps in comprehending why static friction is generally greater than kinetic friction and the underlying mechanisms behind their behaviors.

Frequently Asked Questions

1. Why is static friction greater than kinetic friction?

Static friction is generally greater than kinetic friction because it’s the force that prevents an object from starting to move. It has to overcome the initial inertia and surface roughness. On the other hand, kinetic friction, which acts on an object already in motion, is usually less because the object has already overcome the initial resistance.

2. What makes static friction greater than kinetic friction?

The primary factor that makes static friction greater than kinetic friction is the surface roughness and the interlocking of irregularities between two surfaces. When an object is at rest, more surface irregularities come into contact, leading to higher static friction. Once the object is in motion, fewer irregularities are engaged, resulting in lower kinetic friction.

3. Is static friction always greater than kinetic friction?

In most cases, static friction is greater than kinetic friction due to the initial force required to overcome the inertia of rest and the surface roughness. However, there can be exceptions depending on the materials involved and the specific conditions.

4. Why is the coefficient of static friction greater than kinetic?

The coefficient of static friction is usually greater than the coefficient of kinetic friction because it represents the ratio of the force of friction between two bodies to the force pressing them together. Since static friction has to overcome initial inertia and surface roughness, its coefficient is generally higher.

5. Is kinetic friction ever greater than static friction?

While it’s generally true that static friction is greater than kinetic friction, there can be exceptions. For instance, certain materials or specific conditions may result in kinetic friction being greater. However, these cases are not the norm in everyday physics.

6. Why is static friction higher than kinetic friction?

Static friction is higher than kinetic friction because it has to overcome the initial inertia of an object at rest and the interlocking of surface irregularities. Once the object is in motion, the frictional force decreases, which is known as kinetic friction.

7. What happens when static friction is greater than kinetic friction?

When static friction is greater than kinetic friction, it requires more force to initiate movement. Once the object starts moving, the frictional force decreases, making it easier to keep the object in motion than it was to start the movement.

8. Why is maximum static friction greater than kinetic friction?

Maximum static friction is the maximum amount of friction that can be applied to an object at rest before it starts moving. It’s greater than kinetic friction because it includes the force needed to overcome the initial inertia and surface roughness.

9. Why is the static friction coefficient greater than the kinetic friction coefficient?

The static friction coefficient is greater than the kinetic friction coefficient because it takes into account the greater force required to overcome the initial inertia and surface roughness when an object is at rest. Once the object is in motion, these factors are less significant, resulting in a lower kinetic friction coefficient.

10. What is the difference between static and kinetic friction in terms of motion resistance?

Static friction is the force that resists the initiation of motion, while kinetic friction is the force that resists the continuation of motion. Static friction is generally greater due to the need to overcome initial inertia and surface roughness, while kinetic friction, acting on an object already in motion, is typically less.

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A frictionless surface refers to a hypothetical concept where there is no resistance or friction between two objects in contact. It is a surface that allows objects to move effortlessly without any hindrance. In the real world, achieving a completely frictionless surface is practically impossible, as there will always be some degree of friction present due to various factors. However, scientists and engineers have developed materials and techniques that can significantly reduce friction, creating surfaces that come close to being frictionless. These surfaces have numerous applications in various fields, including transportation, manufacturing, and sports. In this article, we will explore the concept of frictionless surfaces, their properties, and their significance in different industries. So, let’s dive in and uncover the fascinating world of frictionless surfaces!

Key Takeaways

• A frictionless surface refers to a surface that has no resistance or friction when objects slide or move across it.
• Frictionless surfaces are theoretical and do not exist in reality, but they are often used in physics and engineering calculations to simplify calculations and understand the behavior of objects in ideal conditions.
• Frictionless surfaces are commonly used in thought experiments and theoretical models to study the effects of friction and understand the fundamental principles of motion and mechanics.

Examples of Frictionless Surfaces

When we think of frictionless surfaces, we often imagine materials that exhibit properties that minimize or eliminate friction. These surfaces can be found in various applications, from everyday objects to advanced technologies. Let’s explore some examples of materials that possess the characteristics of a frictionless surface.

Motors

Motors are a prime example of where frictionless surfaces are crucial. In electric motors, for instance, the rotor and stator are designed to minimize friction between their moving parts. This allows for smooth rotation and efficient energy transfer. By reducing friction, motors can operate more quietly, consume less energy, and have a longer lifespan.

Roadways

Frictionless surfaces are also employed in the construction of roadways. Highways and race tracks, for example, are often paved with materials that reduce friction between tires and the road surface. This helps to improve vehicle handling, reduce tire wear, and enhance overall driving safety. Additionally, low-friction road surfaces can also contribute to fuel efficiency by reducing rolling resistance.

Low-Truck Beds

In the transportation industry, low-truck beds are designed with frictionless surfaces to facilitate the loading and unloading of cargo. These beds are often coated with materials such as Teflon or other low-friction coatings. By reducing friction between the cargo and the bed, it becomes easier to slide heavy objects in and out of the truck, saving time and effort.

Engines

Frictionless surfaces play a vital role in the operation of engines, where minimizing friction is crucial for efficiency and performance. Engine components such as pistons, cylinders, and crankshafts are carefully engineered to reduce friction. This allows for smoother movement and less energy loss, resulting in improved fuel economy and power output.

Magnetic Levitation Systems

Another fascinating example of frictionless surfaces can be found in magnetic levitation systems. These systems use powerful magnets to suspend objects, such as trains or maglev vehicles, above a track. By eliminating physical contact between the vehicle and the track, friction is greatly reduced. This enables the vehicles to travel at high speeds with minimal energy loss and noise.

Bearings and Lubricants

Bearings and lubricants are essential components in many mechanical systems that require friction reduction. Bearings, such as ball bearings or roller bearings, are designed to provide smooth rotation by minimizing contact between moving parts. Lubricants, such as oils or greases, are used to further reduce friction and dissipate heat in these systems.

Existence of Frictionless Surfaces

Frictionless surfaces, as the name suggests, are surfaces that have no friction. In theory, a frictionless surface would allow objects to move without any resistance or hindrance. However, in reality, frictionless surfaces do not exist. Let’s explore why.

Explanation that frictionless surfaces do not exist in the real world

Friction is a force that opposes the motion of objects when they come into contact with each other. It is caused by the microscopic roughness present on even the smoothest surfaces. These imperfections create interlocking points between two surfaces, resulting in friction.

Friction plays a crucial role in our daily lives. It allows us to walk, drive vehicles, and hold objects without them slipping out of our hands. Without friction, it would be nearly impossible to perform these tasks.

Mention of the inherent roughness of even the smoothest surfaces

Even surfaces that appear smooth to the naked eye have microscopic imperfections. These imperfections can be at the atomic or molecular level. For example, if we were to examine a seemingly smooth glass surface under a powerful microscope, we would discover tiny bumps and irregularities.

These imperfections are responsible for the friction we experience in our everyday lives. When two surfaces come into contact, these microscopic irregularities interlock, causing resistance to motion. This interlocking leads to the generation of heat and the dissipation of energy.

In scientific experiments, researchers have come close to creating extremely low-friction surfaces by using advanced techniques and materials. However, even these surfaces are not truly frictionless. They may exhibit reduced friction compared to everyday surfaces, but they still have some level of resistance.

The Most Frictionless Surface

When it comes to frictionless surfaces, one of the smoothest materials known to us is wet ice. The unique properties of ice make it an intriguing candidate for achieving a nearly frictionless surface. Let’s delve into why wet ice is considered the smoothest surface discovered so far.

Discussion of Wet Ice as the Smoothest Surface Discovered So Far

Wet ice, formed when a layer of liquid water is present on its surface, exhibits remarkably low friction. This phenomenon occurs due to the thin layer of water molecules that form a lubricating film between the ice and any object in contact with it. The presence of this water layer reduces the frictional forces acting on the surface, resulting in a smoother gliding experience.

Ice skaters take advantage of this property to effortlessly glide across the ice rink. The thin layer of water created by the pressure of the skates on the ice reduces the friction between the skate blades and the surface, allowing skaters to move with minimal resistance. This is why ice skating is often described as a graceful and effortless activity.

Reference to the Creation of an Ice-Hockey Field as an Attempt to Achieve a Frictionless Surface

In the pursuit of creating a frictionless surface, scientists and engineers have attempted to replicate the smoothness of wet ice in various applications. One notable example is the creation of ice-hockey fields. Ice-hockey is a fast-paced sport that requires players to move swiftly and change directions quickly. To facilitate smooth movement and minimize friction, ice-hockey rinks are meticulously maintained to ensure the ice surface remains as smooth as possible.

Ice resurfacing machines, commonly known as Zambonis, are used to maintain the quality of the ice surface during breaks in the game. These machines shave off a thin layer of ice and then apply a fresh layer of water, creating a smooth and level playing surface. By constantly resurfacing the ice, the friction between the players’ skates and the ice is reduced, allowing for faster and more controlled movements.

In addition to ice-hockey, the concept of a frictionless surface has also been explored in other fields. For instance, in the field of transportation, researchers are investigating the use of superconducting magnetic levitation (maglev) trains. These trains utilize powerful magnets to levitate above the track, eliminating the need for wheels and reducing friction to a minimum. This technology has the potential to revolutionize transportation by enabling high-speed travel with minimal energy consumption.

Completely Frictionless Surface

Creating a completely frictionless surface in practical terms is not possible. While the concept of a frictionless surface may sound intriguing, it is important to understand the challenges posed by surface irregularities and the inherent inability to eliminate all friction.

The Impossibility of a Completely Frictionless Surface

In theory, a frictionless surface would have no resistance to motion. This means that objects placed on such a surface would experience no force opposing their movement. However, in reality, achieving a truly frictionless surface is unattainable.

Friction is a force that arises when two surfaces come into contact and resist relative motion. It is caused by microscopic irregularities on the surfaces, which interlock and create resistance. Even if we were to smoothen a surface to an incredibly high degree, there would still be imperfections at the atomic level that would result in some level of friction.

Challenges Posed by Surface Irregularities

Surface irregularities, no matter how small, can significantly affect the level of friction experienced. Even on seemingly smooth surfaces, there are microscopic bumps and valleys that can cause objects to encounter resistance when moving across them.

For example, consider a glass tabletop. To the naked eye, it may appear perfectly smooth. However, when viewed under a microscope, one would observe tiny imperfections that create friction when an object is slid across the surface. These imperfections can be caused by manufacturing processes, environmental factors, or simply the nature of the materials involved.

The Inability to Eliminate All Friction

Friction is a fundamental force of nature that cannot be completely eliminated. It plays a crucial role in our daily lives, allowing us to walk, grip objects, and even write with a pen. Without friction, we would struggle to perform basic tasks and navigate our surroundings.

While it may not be possible to achieve a completely frictionless surface, scientists and engineers have developed various techniques to minimize friction in specific applications. These techniques involve reducing surface roughness, using lubricants, or employing specialized materials with low friction coefficients.

Meaning of Frictionless Surface

A frictionless surface refers to a type of surface that offers negligible or zero resistance to sliding motion. It is a concept commonly used in physics and engineering to describe a surface that minimizes or eliminates the effects of friction. Friction, in simple terms, is the force that opposes the relative motion between two surfaces in contact.

Definition of a Frictionless Surface as One with Negligible or Zero Resistance to Sliding Motion

When we talk about a frictionless surface, we are essentially referring to a surface that allows objects to move across it with minimal or no hindrance. In other words, it is a surface that offers little to no resistance when objects slide or glide over it.

Emphasis on the Absence of Friction between the Surface and Objects

The key characteristic of a frictionless surface is the absence of friction between the surface itself and the objects in contact with it. Friction is a force that arises due to the microscopic irregularities present on the surfaces of objects. These irregularities create interlocking points, resulting in resistance when one object moves or slides against another.

On a frictionless surface, these interlocking points are minimized or eliminated, allowing for smooth and effortless motion. This absence of friction enables objects to slide or glide freely without the need for external forces.

Frictionless surfaces are often used as idealized models in physics and engineering to simplify calculations and understand the fundamental principles of motion. While it is challenging to achieve a truly frictionless surface in real-world applications, engineers and scientists strive to minimize friction as much as possible to optimize performance and efficiency.

In the next sections, we will explore the characteristics, properties, examples, applications, benefits, and types of frictionless surfaces to gain a deeper understanding of their significance in various fields.

Existence of a Frictionless Surface

Friction is a force that opposes motion when two surfaces come into contact. It is a fundamental aspect of our everyday lives, influencing how objects move and interact with each other. However, in certain scenarios, the concept of a frictionless surface is often discussed. Let’s explore the existence of such a surface and how it can be artificially created.

Reiteration that frictionless surfaces do not exist in reality

It is important to emphasize that in reality, true frictionless surfaces do not exist. Friction is an inherent property of materials and surfaces, arising from the microscopic interactions between their atoms and molecules. Even the smoothest and seemingly frictionless surfaces still exhibit some degree of friction when examined at a microscopic level.

Friction serves a crucial purpose in our daily lives. It allows us to walk, grip objects, and even drive vehicles safely. Without friction, we would find it incredibly challenging to perform these tasks. Friction also plays a vital role in various industrial processes, such as manufacturing, transportation, and machinery operation.

Mention of the artificial creation of frictionless surfaces

Although frictionless surfaces do not occur naturally, scientists and engineers have developed methods to create artificial frictionless environments for specific applications. These artificial frictionless surfaces are designed to minimize friction as much as possible, approaching the ideal of a frictionless surface.

One method of achieving a near-frictionless surface is by using lubricants. Lubricants are substances that reduce friction between two surfaces in contact. They form a thin layer between the surfaces, allowing them to slide more easily over each other. Examples of lubricants include oils, greases, and even specialized coatings.

Another approach to creating frictionless surfaces is through the use of magnetic levitation. Magnetic levitation, also known as maglev, utilizes the repulsive force between magnets to suspend an object in mid-air. By eliminating contact between the object and any solid surface, friction is greatly reduced or even eliminated entirely.

Furthermore, researchers are exploring the field of nanotechnology to develop materials with unique properties that exhibit extremely low friction. By manipulating the structure and composition of materials at the nanoscale, scientists aim to create surfaces with reduced friction, allowing for smoother and more efficient movement.

Frictionless Surface and Superlubricity

Superlubricity is a fascinating concept that aims to minimize friction between two surfaces, creating a nearly frictionless environment. By understanding the principles behind superlubricity, scientists and engineers have been able to develop materials and techniques that can achieve a frictionless-like effect.

Explanation of Superlubricity as a Method to Minimize Friction

Superlubricity refers to the state where the friction between two surfaces is reduced to an extremely low level. It is achieved by employing various methods and materials that can effectively minimize the interaction between the surfaces. The goal is to create a smooth and effortless sliding motion, akin to sliding on ice.

One of the key factors in achieving superlubricity is the reduction of adhesion between the surfaces. Adhesion occurs when the atoms or molecules of one surface stick to the atoms or molecules of the other surface, leading to increased friction. By minimizing adhesion, the friction between the surfaces can be significantly reduced.

To achieve superlubricity, scientists have explored different techniques such as using ultra-thin coatings, applying lubricants with special properties, and manipulating the surface structure at the nanoscale level. These methods aim to create a barrier or modify the surface properties to prevent adhesion and reduce friction.

Description of Sliding Crystalline Surfaces Under Specific Conditions to Achieve a Frictionless-Like Effect

In recent years, researchers have made significant progress in understanding and harnessing the properties of sliding crystalline surfaces to achieve a frictionless-like effect. Crystalline surfaces are composed of a regular arrangement of atoms or molecules, which can exhibit unique properties when sliding against each other.

Under specific conditions, such as low temperatures and ultra-high vacuum environments, certain crystalline surfaces can exhibit a phenomenon known as “superlubricity.” This occurs when the atoms or molecules of the sliding surfaces align in a way that minimizes the interaction and adhesion between them.

One example of superlubricity on crystalline surfaces is the phenomenon observed in graphite. Graphite is composed of layers of carbon atoms arranged in a hexagonal lattice structure. When two graphite surfaces slide against each other, the layers can align in a way that reduces the friction between them, resulting in a nearly frictionless motion.

Another example is the use of nanoscale crystalline materials, such as diamond-like carbon (DLC) coatings. DLC coatings have a unique structure that allows for smooth sliding motion with minimal friction. These coatings can be applied to various surfaces, including metals and polymers, to reduce friction and improve the performance of mechanical systems.

By understanding the behavior of sliding crystalline surfaces under specific conditions, scientists and engineers can design materials and coatings that exhibit superlubricity. This opens up new possibilities for developing frictionless surfaces in various applications, ranging from high-performance bearings and gears to microelectromechanical systems (MEMS) and nanotechnology.

Frictionless Surface and Magnetic Bearings

Introduction to Magnetic Bearings as a Means to Create Surfaces with Reduced Friction

When it comes to surfaces with reduced friction, magnetic bearings play a significant role. These innovative bearings utilize magnetic forces to suspend and levitate objects, resulting in a frictionless surface. Unlike traditional bearings that rely on physical contact between surfaces, magnetic bearings use magnetic fields to support and guide objects, eliminating the need for any physical contact.

The concept of magnetic bearings revolves around the principle of magnetic levitation, where the repulsive or attractive forces between magnets are utilized to counteract the effects of gravity and create a frictionless environment. By harnessing these magnetic forces, magnetic bearings offer numerous advantages over conventional bearings, such as reduced friction, increased efficiency, and improved precision.

Mention of Magnetic Suspensions and Levitation Using Magnetic Forces

One of the key applications of magnetic bearings is in magnetic suspensions and levitation systems. These systems utilize the repulsive forces between magnets to suspend an object in mid-air, creating a frictionless surface. Magnetic levitation has gained significant attention in various fields, including transportation, energy, and manufacturing.

In transportation, magnetic levitation, commonly known as maglev, has revolutionized the way trains operate. Maglev trains use powerful magnets to lift the train off the tracks, eliminating the need for wheels and reducing friction to almost zero. This allows the trains to achieve incredible speeds while providing a smooth and comfortable ride.

In the energy sector, magnetic levitation is employed in flywheel energy storage systems. These systems use magnetic bearings to levitate a spinning rotor, which stores energy in the form of rotational motion. By minimizing friction, magnetic bearings enable efficient energy storage and retrieval, making them ideal for applications where quick response times and high power density are required.

Furthermore, magnetic levitation finds applications in various manufacturing processes. For instance, in semiconductor manufacturing, magnetic bearings are used to suspend and rotate delicate wafers during the fabrication process. The frictionless surface provided by magnetic bearings ensures precise control and minimizes the risk of damage to the wafers.

Stopping on a Frictionless Surface

When it comes to stopping on a frictionless surface, things can get a little tricky. Without any opposing force to counteract your motion, it’s nearly impossible to come to a complete halt. Let’s delve into the reasons behind this and explore potential solutions.

Explanation that it is not possible to stop on a frictionless surface without an opposing force

On a frictionless surface, there is no resistance to the motion of an object. This lack of friction means that once an object is set in motion, it will continue moving indefinitely unless acted upon by an external force. Without an opposing force to counteract the object’s momentum, it will continue moving at a constant speed.

Imagine you’re on an ice rink with perfectly smooth ice. If you give yourself a push, you’ll start gliding effortlessly across the surface. However, no matter how hard you try, you won’t be able to stop without something to slow you down.

Suggestion of applying an external force in the opposite direction to decrease speed and eventually stop

To overcome the challenge of stopping on a frictionless surface, you need to introduce an external force that opposes the object’s motion. By applying a force in the opposite direction, you can gradually decrease your speed and eventually come to a stop.

One way to achieve this is by using your surroundings to your advantage. For example, if you’re on an ice rink, you can try to grab onto the boards or use your hands to push against the ice in the opposite direction. This will create a force that opposes your motion and helps you slow down.

Another option is to utilize external objects or tools. For instance, you could throw an object in the opposite direction to create a reactionary force that slows you down. Alternatively, you might consider using a parachute or any other device that generates air resistance, which can act as an opposing force and help bring you to a stop.

It’s important to note that while these methods can help decrease your speed and eventually stop on a frictionless surface, they may not be as effective as they would be on a surface with friction. The absence of friction makes it more challenging to control your motion and requires creative thinking to find solutions.

Pushing on a Frictionless Surface

When it comes to understanding the behavior of objects on a frictionless surface, things can get quite interesting. Let’s explore how objects accelerate when pushed on a frictionless surface and the need for an external force to stop their motion.

Description of an Object Accelerating When Pushed on a Frictionless Surface

Imagine a scenario where you have a smooth, frictionless surface, like an ice rink or a polished marble floor. On this surface, you place an object, such as a hockey puck or a ball. Now, if you give the object a gentle push, something fascinating happens.

Due to the absence of friction, the object will start to accelerate effortlessly. Without any opposing force to slow it down, the object will continue to gain speed as long as the external force is applied. This acceleration is a result of Newton’s second law of motion, which states that the acceleration of an object is directly proportional to the force applied to it and inversely proportional to its mass.

On a frictionless surface, the absence of frictional forces allows the object to move with minimal resistance. This lack of resistance enables the object to accelerate smoothly and quickly, making it an ideal environment for studying the principles of motion.

Mention of the Need for an External Force to Stop the Object’s Motion

While it may seem like objects on a frictionless surface can continue moving indefinitely, it’s important to note that an external force is required to stop their motion. Without any opposing force, the object will continue to move at a constant velocity or in a straight line.

To bring the object to a halt, you need to apply an external force in the opposite direction of its motion. This force acts as a counterforce to the object’s momentum, gradually reducing its speed until it comes to a complete stop.

In practical terms, this means that even on a frictionless surface, you cannot rely on friction alone to stop an object. Instead, you need to apply an external force, such as pushing against the object’s motion or using a braking mechanism, to bring it to rest.

Understanding the need for an external force to stop an object’s motion on a frictionless surface is crucial, as it highlights the importance of considering all forces at play when studying the behavior of objects in different environments.

Walking on a Frictionless Surface

Walking on a frictionless surface may seem like an impossible feat, but understanding the role of frictional force can shed light on why this is the case. Frictional force is a fundamental concept in physics that plays a crucial role in enabling us to walk or stand on a surface.

Assertion that walking on a frictionless surface is impossible

It is important to note that walking on a completely frictionless surface is practically impossible. Friction is the force that opposes the relative motion between two surfaces in contact. When we walk, the friction between our feet and the ground provides the necessary grip for us to move forward without slipping. Without friction, our feet would simply slide instead of propelling us forward.

Explanation of the role of frictional force in enabling walking or standing on a surface

Frictional force allows us to walk or stand on a surface by providing the necessary traction. When we take a step, our foot pushes against the ground, creating a force that acts in the opposite direction. This force, known as the normal force, is perpendicular to the surface and prevents us from sinking into the ground.

The frictional force arises due to the interaction between the irregularities on the surface of our feet and the ground. These irregularities interlock with each other, creating a grip that allows us to maintain our balance and move forward. Without friction, our feet would simply slide on the surface, making it impossible to walk or stand.

To better understand the role of friction, let’s consider an example. Imagine walking on an icy surface. Ice is known for its low friction coefficient, meaning it has minimal resistance to sliding. When we try to walk on ice, our feet slide instead of gripping the surface, making it difficult to maintain balance and move forward. This is why walking on a frictionless surface is practically impossible.

Ice as a Frictionless Surface

When it comes to discussing frictionless surfaces, ice often comes to mind. However, it’s important to clarify that ice is not truly a frictionless surface, but rather a slippery one. Let’s delve into the characteristics of ice and how it interacts with objects like skates.

Ice is formed when water freezes, resulting in a solid state with a smooth surface. This smoothness gives the illusion of a frictionless surface, but in reality, there is still some friction present. When an object, such as a skate, comes into contact with ice, friction occurs between the two surfaces.

When skating on ice, the friction between the skate blade and the ice surface allows for control and maneuverability. The skate blade digs into the ice, creating resistance that enables the skater to push off and glide. This friction is essential for maintaining balance and executing various skating techniques.

Although ice is not truly frictionless, it does have significantly less friction compared to other surfaces like concrete or grass. This reduced friction is due to the smoothness of the ice surface, which allows objects to slide more easily. Skaters can take advantage of this reduced friction to achieve higher speeds and perform intricate movements on the ice.

To better understand the concept of friction on ice, let’s take a closer look at how it affects the sport of ice hockey. In hockey, players wear specially designed ice skates with sharp blades. These blades create more friction with the ice, allowing players to stop quickly, change direction rapidly, and maintain balance while maneuvering on the slippery surface.

What is the relationship between frictionless surfaces and acceleration?

The concept of a frictionless surface is key to understanding various aspects of motion, including acceleration. A frictionless surface eliminates the force of friction between objects, allowing them to move without any hindrance. When exploring the topic of acceleration on a frictionless surface, we can delve into how the absence of friction impacts an object’s ability to change its velocity over time. To gain a deeper understanding of frictionless surface acceleration concepts, it is beneficial to read more about it through “Understanding frictionless surface acceleration concepts”.

Frequently Asked Questions

What is a frictionless surface?

A frictionless surface refers to a hypothetical surface that has no resistance to motion when an object slides or moves across it. It is characterized by the absence of friction, which is the force that opposes the relative motion between two surfaces in contact.

Does a frictionless surface exist?

No, a frictionless surface does not exist in reality. It is a theoretical concept used in physics to simplify calculations and understand the behavior of objects in idealized conditions. In the real world, all surfaces have some level of friction, although it can be minimized or reduced in certain cases.

What does frictionless surface mean?

A frictionless surface refers to a surface that offers no resistance or frictional force when an object moves or slides across it. It is an idealized concept used in physics to simplify calculations and analyze the behavior of objects in the absence of friction.

What is the most frictionless surface?

In theory, the most frictionless surface would be one that offers absolutely no resistance to motion. However, in practice, it is impossible to achieve a completely frictionless surface. Certain materials, such as superconductors or superfluids, exhibit extremely low levels of friction, but they are not entirely frictionless.

What is an example of a frictionless surface?

An example of a frictionless surface is a perfectly polished ice rink or a well-lubricated air hockey table. Although these surfaces are not completely frictionless, they offer significantly reduced friction compared to other surfaces, allowing objects to glide smoothly with minimal resistance.

What is the definition of a frictionless surface?

The definition of a frictionless surface refers to a surface that lacks any resistance or frictional force when an object slides or moves across it. It is an idealized concept used in physics to simplify calculations and analyze the behavior of objects in the absence of friction.

What are the characteristics of a frictionless surface?

The characteristics of a frictionless surface include the absence of frictional force, smoothness, and the ability to allow objects to move or slide with minimal resistance. Frictionless surfaces are hypothetical and do not exist in reality, but they are used in theoretical physics to study idealized scenarios.

What are the properties of a frictionless surface?

The properties of a frictionless surface include the absence of friction, low resistance to motion, and the ability to minimize energy loss during movement. Frictionless surfaces are theoretical constructs used in physics to simplify calculations and understand the behavior of objects in idealized conditions.

What are the applications of a frictionless surface?

Frictionless surfaces have various applications in different fields. In physics, they are used to study idealized scenarios and simplify calculations. In engineering, frictionless surfaces are employed in the design of bearings, gears, and other mechanical systems to reduce energy loss and increase efficiency.

What are the benefits and importance of a frictionless surface?

The benefits of a frictionless surface include reduced energy loss, increased efficiency, and smoother motion. Frictionless surfaces are important in various industries, such as transportation, manufacturing, and sports, as they help minimize wear and tear, improve performance, and optimize energy consumption.

How does a frictionless surface work?

A frictionless surface works by minimizing or eliminating the frictional force between two surfaces in contact. This can be achieved through the use of lubricants, specialized materials, or by reducing surface roughness. However, it is important to note that achieving a completely frictionless surface is not possible in reality, and the concept is used primarily in theoretical contexts.

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First and foremost, to answer fixed pulley vs movable pulley, we differentiate the pulleys in a few points, and afterward, we will likewise talk about them separately.

Both fixed and movable pulleys are used to lift heavy objects. The rotating axis is the main difference between fixed and movable pulleys. The first has a fixed axis of rotation, and the latter has a movable axis of rotation, as their names suggest.

We’ll start with the fundamental concept of a pulley before going into a fixed pulley vs movable pulley in depth.

The pulley:

A string or rope is wound around the grooved rim of a wooden or metal disc to create the pulley. The disc revolves around its axis, which runs through the centre.

There are two ways to use a single pulley: 

• As a fixed pulley 
• As a movable pulley.

Let’s talk about fixed pulley vs movable pulley, which is the focus of this post.

Fixed pulley vs Movable pulley: Points to remember

The following describes the difference between fixed and movable pulley:

Parameters	A Fixed pulley	A Movable Pulley
Definition	The axis around which the disc rotates is fixed.	The axis around which the disc revolves is movable rather than fixed.
The Load attachment	Here the load one wants to lift is attached to the one end of the rope.	Here the load one wants to lift is attached directly with the pulley.
The direction and magnitude of force	This pulley can only change the direction of the force but can not change the magnitude of the force.	This pulley can change the direction of the force as well as the magnitude of the force.
Use	It is the one which provides better direction to apply effort.	It is the multiplier of force.
M.A.	This pulley’s mechanical advantage is 1.	This pulley’s mechanical advantage is 2.
V.R.	This pulley’s velocity ratio is 1.	This pulley’s velocity ratio is 2.
Example	Pulley used in well	Pulley used in zip lining

Let’s have a look at both pulleys independently now.

A Fixed Pulley:

Fixed pulley refers to a pulley system in which the pulley is mounted to a fixed point and the load is attached to one end of a rope with negligible mass that passes through the grooved rim of the disc or wheel.

Due to load, one side of the rope will be stretched. The stretching creates tension in the rope. The load and the tension created in the rope will have opposite directions. But as the load is the cause of tension, it will have the same magnitude as that of the load applied. If we represent applied load as L and rope tension as T, we can write:

L = T

On the other side of the rope, the person is applying effort to lift the object. Thus, due to effort, again, the rope is stretched, and tension is created. Here the tension is due to effort applied by a person; thus, both have the same magnitude but have opposite directions.

If we represent applied effort as E, we can write:

E = T

Thus, mechanical advantage of fixed pulley is:

∴ M.A. =1

Thus, a fixed pulley does not give you any kind of mechanical advantage. It only provides you a better direction to lift an object with all your weight. It means you need to apply the effort as that of the load weight.

L = E

As the load and effort are the same in magnitude, the distance travelled by both will also be the same. Thus, if we represent distance travelled by the load as L_d and distance travelled by effort as Ed, then we can write:

L_d = E_d

If both distances take the same time to travel, then the velocity ratio is:

∴ V.R. = 1

Thus, efficiency of fixed pulley:

∴ ???? = 100%

Thus the load is lifted upward, same as you apply effort in a downward direction. 

The pulley used in the well, flag pole are examples of the fixed pulley.

A Movable Pulley:

A movable pulley refers to a pulley system in which the pulley is directly attached to the load. One end of a rope with negligible mass that passes through the grooved rim of the disc or wheel is attached to the fixed point, and the other end is free. 

The free end of the rope is used to apply the effort. The load is kept with the pulley between the fixed end and a free end of the rope. Thus, due to the load, there will be tension on both sides of the rope. As load is responsible for the tension in both sides of the rope, we can write:

T + T = L

∴ L = 2T

Now, the applied effort also creates tension in the rope. Thus, we can write:

E = T

∴ L = 2E

Thus, the applied effort will be half of the load.

Thus, mechanical advantage of movable pulley is given by:

∴ M.A = 2

It shows that with lesser effort, more load can be lifted. Thus, this pulley is used as a force multiplying machine.

Now the distance travelled by effort will be doubled from a distance travelled by the load. This happens because by applying effort, not only load but the rope with a fixed point is also lifted. Thus, velocity ratio for movable pulley is:

V.R = 2

Thus, efficiency of a movable pulley is:

???? = 100%

The pulley used in the modern elevator, construction crane are examples of the movable pulley.

The 100% efficiency is only possible in ideal conditions, as friction is always present in reality.  As a result, in reality, M.A. is always < 1, and thus efficiency ???? is also always < 100%.

What does the movable pulley do that a fixed pulley does not? 

A fixed and a movable pulley are both used to lift heavy objects.

A fixed pulley can only provide you a better direction to lift an object. But a movable pulley helps you to lift an object with half of the effort than the load. Thus, using a movable pulley for the same load effort can be reduced, but this can not happen with a fixed pulley.

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The changes that can reverse and, in the same cases, remain irreversible are generally physical changes. Let us see how can a physical change occur. 

The physical change occurs when the changes take place in the physical properties of the substance or the object. The changes in shape, size, or state can be brought in different ways, either by the transfer of energy, heat, or physical means. 

The physical changes can occur by the following means:

• Cutting/Breaking
• Melting
• Freezing
• Boiling
• Dissolving
• Mixing

Cutting/Breaking 

When we cut, break, or tear something, the size or shape gets deformed. Due to this type of alternation, a physical change occurs. For instance, when we cut fabric to make a dress, it is a physical change. The fabric and the dress are made of the same chemical composition, secondly on breaking a pencil or a crayon, its shape and size change. The pieces still remain the part of a pencil. Hence on breaking or cutting, a physical change occurs that brings alterations in the shape and size of the object. 

Melting

Melting is another way by which a physical change can occur on melting the phase or, say, the state of the substance changes. When the ice cream starts melting, it changes into a liquid state, but the taste and all the chemical characters continue to stay the same as that of the solid or semi-solid ice cream. On melting, we receive a liquid version of ice cream,m. Now, this process is reversible, and we can gain the original state of the ice cream back. So this proves that on melting, the physical change takes place. 

Freezing 

For making jelly, the mixture has to be cooled and frozen. When we do so, the liquid state of jelly gets converted into a solid or semi-solid state. During this process, only the state changes, and all the internal composition remains the same. It does not involve the breaking of bonds or the formation of new bonds. Hence this change can be inferred as the physical change. We know that it is only a temporary change as the process can be reversed at high temperature. Through this example, we understand that freezing is another process that causes a physical change to occur. 

Boiling

Boiling can also bring physical changes to occur. It causes the phase change of a substance. When we boil water at its boiling point, the water changes into vapor form. Now, water is liquid, and vapor is gaseous. So changes occur in the state of water, but the chemical formulas of both states are the same. The vapor can be reversed back into the water by the process of condensation. So on boiling, the physical change occurs. 

Dissolving

Dissolving is the process in which we add solute particles into a solvent and make a solution. When we dissolve two substances together, there is no release or intake of energy, and hence internal energy remains the same. The solvent molecules get further apart, and solute molecules get inserted. It does not lead to the emergence of any new substance, and therefore the whole process is the physical change. The example of dissolving is salt and water. On evaporation, the salt can be generated back. Hence on dissolving, the physical change occurs. 

Mixing 

Mixing also causes a physical change to occur. When we mix different colors, we obtain a new color. Only a different color is generated; no new substance is formed. Therefore mixing also causes physical change. In some cases, the change is reversible, and in others, it is irreversible.

Frequently Asked Questions (FAQs)

Is freezing a chemical or physical change? 

The everyday changes happening around us can be categorized as physical change or chemical change.

The process of freezing is a physical change. The reasons are simple as it does not lead to the formation of any new substance. The change is caused only in the phase. Also, the substance can be brought back to its initial state. Hence freezing is a physical change.  

How can a physical change occur?

The numerous physical changes occur all around us in different forms.

The physical change occurs through physical means. The change in physical characteristics of objects like length, structure, or state is known to be a physical change. 

Which process leads to physical changes? 

The changes in physical characteristics of a substance are said to be physical changes. 

The melting, freezing, cutting, dissolving, and other such types of physical processes lead to the occurrence of physical change. All these processes can either be reversed or stay the same. They cause changes in physical properties. 

Give five examples of physical change. 

Physical change is the transformation caused by the physical properties of the substance. 

The five examples of physical change are melting ice, cutting trees into logs, tearing paper, dissolving sugar into water, and folding clothes. All these changes involve alterations in the size, shape, and phase of the object. They are either reversible or irreversible. 

Is the growth of plants a physical change or a chemical change?

The whole process of the growing tree is both a physical and a chemical change example. 

The growth leads to an increase in the height and width of the tree; therefore, it is considered a physical change. At the same time, growth involves the photosynthesis process; therefore, it is also a chemical change. So a growing tree is both a chemical and physical change example. 

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Friction is retarding force applied to an object to restrict the movement of the object which is in contact with another object.

The friction is classified into two types based on their properties, behavior, and state of the matter as “dry friction and fluid friction”. This article is focused on the study of what is dry friction and types of dry friction.

What is dry friction?

To answer the above question, consider an example of pushing an object which moves in contact with another. When an object is pushed over a surface, the motion of the object and the applied force act in the same direction, but the object never moves so quickly it takes too much force to move. The motion is retarded by force is called friction.

The dry friction is defined as “The force of resistances offered between the two solid surfaces in contact with each other retards the relative tangential motion in the opposite direction.”

Interesting Facts

• Usually, dry friction is used as a synonym for “Friction”.
• The dry friction evolve between the solid surfaces is corresponding to the normal force acting on the surfaces.
• The magnitude of the area enclosed between the two surfaces in contact does not involve dry friction.
• The nature of the material which is to be experienced the frictional force may affect the dry friction.
• Dry friction depends on the nature of the contact materials. It is measured by a unitless quantity called “Coefficient of friction.”
• Roughness of the surfaces does not affect the dry friction in case of some exceptional materials.
• The area between the two contact surfaces is the individual quantity, which does not affect the dry friction.
• The velocity at which the object is moving does not affect the dry friction only when the velocity is low.
• The angle between total resultant friction acting between the two surfaces and the normal force exerted on the surfaces is called the angle of friction.
• The applied force and the friction force are equal as long as the object is at rest.

Types Of Dry Friction

Dry friction is applicable for non-lubricant materials. It is classified mainly into two types based on their properties. They are;

• Static friction
• Kinetic friction

These two types of dry friction exhibit distinct behavior, characteristics that we are going to study in this section.

Static friction

A tendency of an object to keep it at rest is called static friction.

When you try to push a table or a shopping cart, you exert more force on the table for the first push. Do you ever think why the first push is always so harder?

Yes, because static friction is acting on the cart or table. It hinders the motion of the table or card which is at rest when you try to push for the first time. Meanwhile the table tries to overcome this friction after the first push. So you feel little ease to push after the first push.

So the static friction is defined as “the friction that exerted on the stationary body without triggering the motion of another body which is in contact.”

The expression for the static friction is given using the inequality equation.

F_s ≤ µ_s N

Where F_s is the force of static friction

             µs is the coefficient of static friction

             N is the normal force acting between the two surfaces.

Facts of static friction

• The area occupied between the two contact surfaces influences the static friction.
• The increase in the normal force acting on the surfaces makes the maximum external force applied on the stationary surfaces also increases. This means that normal force and applied force are proportional.

Limiting static friction

The maximum static friction exerted on the body, which is about to move over the surface of another body, is called the limiting static friction.

When we exert more force on the stationary body, it overcome from the limiting friction and begins to move. As the body is no more in the stationary state, this leads to another type of friction called Kinetic friction.

Kinetic friction

The kinetic friction is also called “dynamic friction.” It is the force that acts between moving body.

When you roll a ball, you have experienced this friction. When the ball is rolled on the surface, its motion is retarded by some force exerted on the ball, and motion is held back. This is due to the kinetic friction.

So, kinetic friction can be defined as “the friction force acting between the surfaces which are in relative motion with each other, experiences the resistance in the opposite direction.”

The kinetic friction acting on the object is given by the formula

F_k = µ_kF_N

Where; µ_k is the coefficient of kinetic friction.

And F_N is the normal force.

When the surface is in the horizontal direction, there is no vertical component of force. Then the normal force is F_N = mg.

F_k =mgµ_k

The kinetic friction is subdivided into two types

• Sliding friction
• Rolling friction

Sliding friction

It is the friction produced when a body slides over the other body so that the relative motion of the body is resisted.

It is given by the formula,

F_s = µ_s F_N

Where; µ_s is the coefficient of sliding friction.

F_N is the normal force acting on the object.

It is observed that the formula for sliding and static friction is almost the same but value of sliding friction is always less than the static friction.

Rolling friction

It is friction when the body is rolled on the surface of another body. The relative motion of the body is retarded.

It is given by the formula

F_r = C_rr F_N

Where; C_rr is the coefficient of rolling friction

F_N is the normal force acting on the body.

Need to know facts

• The rubbing of two objects is kinetic friction. When the two objects are rubbed, heat is produced. This is because kinetic friction is transform as thermal energy.
• Lubrication prevents kinetic friction, which is involved in the wear and tear of the machine parts.

Facts of kinetic friction

• The kinetic friction and the normal reaction between the surfaces are proportional to each other.
• Kinetic friction depends on the roughness of the contact surfaces.
• The shape, size, and area of the contact surfaces do not influence the kinetic friction.
• The velocity at which the surfaces are moving in contact does not affect the kinetic friction. The velocity of the surface and object are almost equal, there is no much variation between them.

The variation of dry friction with the applied force is represented below the graph, which gives the value of static and kinetic friction.

Coefficient of friction

The coefficient of friction gives the relation between the two objects in contact and the reactions that acting between those objects.

It is defined as “the ratio of the two materials moving one over the other and the force holding to be in contact with each other.”

The Greek alphabet “µ” is the symbol to represent the coefficient of friction. Different materials exhibit different friction coefficient. It ranges from zero to greater than 1. Usually coefficient of static friction is greater compared to the kinetic friction.

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The physical process of transport of heat involves many processes. In this post, we are going to know the difference between Conduction Vs Convection.

Conduction is a method of transferring heat molecules between two objects in direct contact with each other. But in convection, the mode of transport of heat molecules is within the fluid matter is due to differences in density regions. Both methods occur in different states of matter.

Now let us learn about Conduction Vs Convection in depth.

Conduction Vs Convection cooling

Both conduction and convection also help in the process of cooling specific devices.

Conduction Cooling

• It is generally defined as the transport of heat from the hotter component to the cooler part.
• Example: Conduction is the essentially used mode of heat transfer because, in all the power supplies, the heat sinks are used to transfer the heat away from the boiling appliances.

Convection Cooling

• It is defined as the transfer of energy between two systems of objects which involves the movement of the massive bulk of the fluid.
• Example: The fans’ built-in ovens and many other devices provide convection cooling. Even the air present in our surroundings provides cooling naturally.
• Some heavy power applications contain heat sinks that depend on cooling through convection; it helps transport heat far from the appliances to cooler air.

These are some differences between Conduction Vs Convection cooling.

Heat transfer rate Conduction Vs Convection

The heat transfer rate between conduction and convection differs like matter.

• The heat transfer rate of conduction depends on the thermal difference between two systems of substance where the transfer is due to direct contact. It usually transfers at a lower rate than convection.
• The rate of flow of heat molecules also depends on the nature of matter. Since the two processes happen in different matters, i.e., solids (conduction) and fluids (Convection).
• Conduction is mainly due to collision, affecting heat transfer and convection due to area, temperature, density, etc.

There is a change in the rate of transfer of heat of conduction and convection.

Conduction Vs Convection vape

The method of heat transfer is in use to vaporize certain products, and the primary difference is as given below;

• The convection mode of heat transfer is always superior in comparison to conduction.
• If we take the example of terpenes, there is a high exposure of heat in conduction, which leads to a lot of waste products; direct heat exposure destroys the materials. While in convection, it helps to revert all the materials of terpenes.
• Conduction uses the direct mode of heat transfer to vaporize the substances, passing over the surface to remove the vapors from objects, say a herb. In contrast, the convection process is used in vaporizers that concentrate with hot air on a surface, not directly removing vapors.

Both conduction and convection vaporizers are in use to remove vapors from many appliances.

Conduction Vs Convection

The primary difference between conduction and convection is given in the below table,

COMPARISON	CONDUCTION	CONVECTION
Definition	It is a heat transfer process between two objects in direct contact and occurs due to free electrons present in the system.	It refers to the mode of heat transfer that occurs in fluid in which energy is transmitted from one region to another.
Direction	It is through direct contact	Horizontal path
Nature of process	Physical process	Physical process
Mode of heat transfer	Solid objects	Intermediate systems
Speed	Slow process	Fast process
Effect	Occur because of temperature difference.	Occur because of the difference in mass density.
Appearance	Through the collision of molecules.	Due to transport of matter.
Laws	Both reflection and refraction laws are absent.	Both reflection and refraction laws are absent.
Example	Hand and cup of hot tea	Steam of hot beverage.

Therefore, conduction and convection are two essential methods of heat transfer.

Read about: Examples of convection

Conduction: How does it work

Conduction is one of the methods of transport of heat molecules in heated solid materials.

• Conduction happens between the two substances or objects that are directly in contact with one other.
• It generally happens when temperature increases; due to this, the heat molecules start to vibrate; these vibrating molecules collide with neighbor molecules and make them vibrate; heat is transferred from the hotter region to the cooler area.
• The main consequence for conduction to take place is due to the variation in temperature between the two substances that are together.
• It is mainly seen in solid substances.
• The collision of molecules occurs in a straight path.

It is how a conduction process occurs in the matter.

Factors affecting conduction and convection heat transfer

The factors which affect the conduction mode of heat transfer are as follows,

• Area of the cross-section.
• Time is required for the process to complete.
• Heat molecules travel the length of distance.
• Temperature.
• Nature of matter.

They are some of the critical factors which affect heat transport.

Peclet number

Peclet is a number used to indicate the thermal transfer of heat within a matter.

Peclet is a dimensionless number used to denote the ratio of flow of matter, especially by thermal conduction. It is also obtained by multiplying Reynolds and Schmidt numbers. The formula to calculate Peclet number is as follows,

Where,

u = fluid velocity,

L = characteristic dimension

k = thermal diffusivity of the fluid.

Re = Reynolds Number and

Pr = Prandtl Number

Peclet number is different for all the modes of heat transfer.

Rayleigh number of convection

The convection number, which is also known as Rayleigh-Benard Convection, is a vital phenomenon discovered.

It is a type of natural convection. The convection number is dimensionless, obtained when there is a flow of heat in a horizontal path. The convection appears due to the factors of gravity and buoyancy. The formula is as given below.

Where,

T_u = temperature of the upper plate

T_b = temperature of the lower plate

L = height of the container

g = Acceleration due to gravity

ν = kinetic of viscous fluid

α = Thermal diffusivity

β = Thermal expansion coefficient

It is a significant number to calculate the rate of convection in a material.

Examples of conduction and Convection

Several examples happen in daily routines in which we experience conduction and convection.

While frying some ingredients in the pan, heat transfer from stove flame to the bottom of pan and then to the elements. It is an example of conduction.

But in the case of convection, when you take any liquid in the pan and heat it at the bottom, the molecules of fluid will be able to move freely, and interchange occurs between hot and cold molecules.

We observe that when we heat one end of the rod, the other end would automatically heat up because of the convection process of transport of hot molecules from one end to the other end. In the case of conduction, the molecules of matter transfer heat directly to neighboring molecules, and the movement of heat occurs.

When you take any hot beverages, you feel warmth, and it is because of conduction. In the same hot drinks, the steam observed is due to convection.

These are some essential daily routine examples of conduction and convection.

Frequently Asked Questions on conduction and convection| FAQs

Do conduction and convection need matter to transfer heat?

The mode of heat transfer conduction and convection require matter for the process to occur.

If there are two systems that are in contact with each other and if there is a variation in temperature difference between the systems, then the transport of heat happens between the two temperature regions.

Can conduction and convection processes happen together?

The conduction and convection process of heat transfer cannot happen simultaneously.

When heat transfer takes place in a fluid, it is by anyone mode, i.e., convection or conduction. It always depends on the quantity of fluid present. Hence, it is possible to say that the two ways of transfer of heat cannot happen together.

What state of matter can undergo conduction and convection heat transfer?

Conduction and convection depend on the nature of matter to transfer heat.

Conduction usually occurs in solids, but there is no chance of convection due to their molecular structure. Hence, convection can happen only in fluids (gases and liquids) and conduction in solids.

Can the conduction and convection process happen in a vacuum?

Vacuum is different compared to gases or air.

A vacuum is known as a space where matter cannot be seen. Both heat transfer conduction and convection cannot happen in a vacuum due to the absence of states of matter. The heat transfer method that can be seen in a vacuum is the radiation mode of transfer.

State Fourier law of conduction?

The critical law of heat conduction which Fourier states, is given as follows,

The law states as follows, “The rate of flow of heat transport through an object is directly proportional to the region of negative gradient of temperature and area, measures at normal to the gradient, through which heat transports.”

                                                                   Q = -kAdT / dx

where,

The Q= time interval during which the amount of heat 

A= cross-sectional surface area.

dt= the temperature difference between the ends.

dx= the distance between the ends.

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The reason why is critical damping faster than overdamped is because of the fact that critical damping moves to equilibrium state than the overdamping.

Critical damping is applying a resistive force against the oscillating system to bring it to stop it at once. Damping is when a strong resistive force is applied against the motion of an object that is undergoing simple harmonic motion.

Explaining why critical damping is faster than overdamping. A girl on swing will be swinging forever if there wasn’t any air resistance force. But a force must be applied to bring the swing to rest that is when displacement is zero. When displacement is zero, the system is said to be in equilibrium.

When a force is applied to the motion, that is damping applied, the swing moves in a way that the amplitude lowers slowly. This is called as light damping. When a strong force is applied against the motion then the swing is slowed down and the amplitude lowers further more.

Now when there is an even stronger force applied on the swing, it goes past the point of equilibrium and comes back. The force acts negative here and finally the swing comes to rest as quickly as possible making the displacement zero. This is known as critical damping.

Why critical damping is faster than overdamped and this is the reason behind it. At critical damping the oscillating system moves to equilibrium as soon as possible than overdamping.

Why is critical damping faster than overdamped

In an oscillation system, overdamping means the oscillations come to rest after a long time after applying the resistive force. Light damping means the oscillation come to rest gradually. But critical damping means the oscillations come to rest immediately.

A damping system becomes critically damped when the damping factor is (ζ = 1). As the zeta (ζ) value goes more than 1 the system response will become slow and the vibrations or oscillations will take a longer time to reach the equilibrium position.

When ζ values goes lower than 1 the oscillation will gradually come to rest that is it will return to the equilibrium position at a slow pace.

When,

      (ζ)  = 1; critical damping

      (ζ)   = >1; overdamping

  (ζ)   = <1 ; underdamping.

From the above cases we can come to a conclusion that, critical damping is the threshold point above which the overdamping occurs that is equilibrium position attained at a very slow rate. And below which it is known as underdamping that is when the equilibrium position is reached gradually.

So from the observation it is known that critical damping means the return to the equilibrium position of an object under motion is faster than the overdamping.

Frequently Asked Questions

What does critical damping mean?

Critical damping is the threshold point between the overdamping and the underdamping.

For critical damping, the damping factor is equal to 1. When the damping factor goes more than one it is known as overdamping. And when the damping factor goes below 1 it is known as the underdamping.

Which system is considered to be critically damped system?

A system which has the smallest value of amplitude is known as the critically damped system.

The smallest value of amplitude also means that the oscillation or the vibrations of a system is the zero having no value. The system reaches equilibrium position at faster rate. This value separates the non-oscillations from the oscillation.

Why does overdamped take a longer time?

The overdamped takes a long time because it reaches the equilibrium position after a very long time.

Since the damping factor in an overdamped system is more than 1 the system takes a long time to respond and also to reach a steady-state position. The amplitude in this system reduces slowly. This is exactly why critical damping is faster than overdamped.

What is an example of critical damped situation?

Automobile shock absorber is a very good example of critically damped situation.

Critical damping means putting a stop to the vibrations or oscillations to a system under motion. This shock absorber is a device in an automobile which has a control over the mounted device that is in the form of spring mounted.

How is overdamped, underdamped and critically damped system distinguished?

The damping factor the return of the system to the equilibrium position distinguishes the system if it is overdamped, underdamped or critically damped.

When a system returns to the equilibrium position at once with zero vibrations or oscillations it is known as critical damping. Here the damping factor is 1.When a system takes a very long tome time to reach the equilibrium position it is known as overdamped. The damping factor is more than 1. When a system gradually comes back to the equilibrium position it is known as underdamped. The damping factor is less than 1.

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The physical change types are defined depending on the phase transition process, which converts the substance’s physical properties. The article discusses about the physical change types, which are listed below: 

Read more about the Physical Change Properties.

Dissolution or Dissolving

When we pour solid salt into water liquid, the salt switches its state from solid to liquid into the water and becomes a different solution. The process responsible for converting the salt’s state is named “dissolution” and depend on solubility of solid.

The salt act as a solute, which dissolves into the solvent to produce a different solution. The water liquid act as a solvent that can dissolve the solute. Even the salt is dissolved into water, its chemical formula (NaCl) remains the same in the water.

Melting or Thawing

When we heat a solid substance like metal, glass, etc., it increases the substance’s internal heat. Every substance has its melting point. Therefore, on the continuous heat, the substance’s internal heat goes beyond its melting point, increasing the energy of its internal particles.

The internal particles move away from each other, increasing the interatomic distance. Therefore, the solid substance melted to form a liquid. 

Boiling

Every liquid has its boiling point. Hence, if we continue the heating to liquid, its internal heat approaches beyond its boiling point, contributing more energy to its internal particles. Because of the rise in their interatomic distance due to constant heat, the liquid state boiled to become a gaseous vapor.

Read more about Physical Change Heat Examples.

Evaporation

Like the boiling process, evaporation also turns liquid into gas vapor; but it is due to natural heat only. When we put a water-filled bowl into direct sunlight, we notice the empty boil after a couple of hours, as the water evaporates by sun heat.

Such natural heat quickens the internal particles of liquid to move rapidly, which escape them as particles of gas vapor into the atmosphere.

Boiling Vs Evaporation

Boiling	Evaporation
It requires both artificial heat and natural heat.	It requires only the natural heat of the sun.
The rate of boiling is fast.	The rate of evaporation is slow.
The process happens to the whole liquid mass.	The process only occurs on the surface level of liquid.
The vapor pressure of liquid overwhelms the atmospheric pressure.	The vapor pressure of a liquid cannot be able to overcome atmospheric pressure.
Hence, a bubbling appears in liquid.	Hence, a bubbling cannot appear in liquid.

Sublimation or Lyophilisation

It is a unique phase transition process that converts the frozen solid into gas using the natural vacuum heat without transforming it into liquid. Like melting and boiling points, every substance has its triple point – the temperature at which all three states of a substance coexist in equilibrium which cause sublimation of substance.

The process occurs below the substance’s triple point, corresponding to the lowest temperature at which the substance can exist as a liquid. The sublimation process is a low-temperature dehydration process, also called freeze-drying that preserves the natural food such as vegetables or fruits by first freezing it, decreasing the surrounding pressure, and then transforming the ice by sublimation.

Condensation or Clouding

Like triple point, every substance in the gas state has its dew point – the temperature at which the gaseous air requires to be cooled at constant pressure and the air is not able to handle the water in gaseous form. Therefore the hot vapors from rainwater condense into low temperature of sky to create the clouds. That’s why the condensation called as “clouding“.

During condensation, the internal particle of gaseous vapors drops the energy of heat when reaching the cold surfaces, converting gaseous vapors into liquid. The hot vapors condense on cold surfaces like mirrors of showers or steel cover placed on a pan while cooking; to form tiny water droplets.

Vaporization

It is the physical change type that turns solid or liquid into gas vapor. Depending on conversion between states, it is subdivided into three other types: boiling, evaporation, and sublimation, as all three processes obtain gas as the final state.

Out of three types, the sublimation process turns solid into a gas. In contrast, boiling and evaporation involve the conversion of liquid to gas, but the difference between both processes is heat difference.

Smoke Formation

When we burn solid substances like wood, paper, coal, etc., they release their energy in heat and turn into two new products such as ash and smoke. That’s why smoke is called the byproduct of fire. Since the substances are carbonaceous, they release carbon-containing compounds in the air throughout their combustion process.

The smoke is a hot vapor of carbon dioxide gas produced when a combusted substance combines with the air; and it includes all three states of matter such as gases, liquid, and solid carbonaceous compounds.

Solidification or Freezing

Like dew point, every substance in a liquid state has a freezing point. Therefore, when we lower the temperature of a liquid below its freezing point by cooling it, it gradually freezes to become a solid substance. That’s why the process called ‘solidification’.

Cooling the substance, its internal particles drop the energy, which reduces their interatomic distance to form a solid, is called ‘nucleation’. The solidification process is employed to give diverse shapes to the solid. For example, a liquid state such as molten metal or melted wax is solidified to form a solid state of metal or wax of different shapes.

Liquefaction

It is the physical change type that turns gas or solid into a liquid. The conversion between states has subdivided the liquefaction process into three other types: melting, heating, and condensation; as all three processes obtain liquid as the final state. But the difference between all three processes is heat difference.

The gases can be liquefied by cooling or condensation. That means gas can be transformed into a liquid state when it is cooled below its boiling point. For example, gaseous nitrogen liquefied or condenses to form a nitrogen solution.

The solid can be liquefied by heating or melting. That means a solid can transform into a liquid state when it is heated above its melting point. For example, solid coal is liquefied or melted to yield liquid fuels.

Frost Formation

The frost formation is similar to the deposition process, where liquid and gas are deposited into a cooled surface to produce a solid. The process is a combination of solidification of water liquid and condensation of gas vapor.

When the temperature of the solid substance decreases to the freezing point of water, and the dew or condensation point of the adjacent air on surrounding, the layer of ice develops on the solid substance. Therefore, we can recognize the frost or icing on the window panes and grass in the winter season. Since the process is naturally occurring, its rate is slow.

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