Is Potential Energy Stored Energy: Why, How, Detailed Facts


In our daily life, we come across the word potential energy; now the question arises, Is potential energy stored energy. To know the answer to the question, read the full article.

The universe is made up of energy and matter. The matter is whatever we see around, which has mass, occupies space and energy is possessed by the system or body to do work. There are different types of energy, and all of them will fall in two primary forms- Kinetic and Potential energy.

Is potential energy stored?

If anything is in motion, we say it has kinetic energy. And If the potential energy is due to the position or due to the configuration of the body or system, then does it mean potential energy is stored?

Yes. The potential energy is a stored form of mechanical energy.

Gravitational Potential Energy

Do you know? Any object which is moving or at rest are always under the effect of gravitational field. When a body is kept in gravitational field, its capacity to do work comes from the interaction of that system or body with the field.

Depending upon the height from the surface (which is taken as reference), the object has gravitational potential energy. Let’s say if an object or system is kept at height h from the earth’s surface; it has gravitational potential energy, which is given by

P.E. = m*g*h

Where, m=mass,

g= gravitational acceleration,

h=height from the reference point,

Elastic potential energy

When a spring is compressed, or rubber is stretched, the work done on it is, in stretching or compressing, stored in the form of elastic potential energy. As soon as the spring or rubber is released the stored energy transforms its form and does work.

Is potential energy stored or released

In nature, there is a lot of energy which is not available to do any work unless and until it released, And which is stored in the object due to one of two things, 1) object’s interaction with the force-field (i.e. gravitational field) 2) physical configuration of the object which can possibly store energy in a particular configuration and releases in another i.e. spring, is potential energy.

Is potential energy always stored

The resting form of energy in any object or body is Potential energy. 

When we say the object or system has potential energy, it means if we allow the system to change its configuration or its position, then the system could do work or release its energy in another form (kinetic energy).

                                                            Work done= change in energy

Have you played with the spring? Remember, we used to keep one block on one end, and then we used to compress it. As soon as we released it, the stored potential energy in the spring was free to work, so it applied force on the block and pushed it away with great energy.

You must have seen the waterfall. It looks beautiful, right? The stream of water falling from the hill has tremendous energy. The scary sound coming from it alludes to the same. The water, held at height have potential energy, when it falls from the height the energy (due to the height) converts into kinetic energy.

is potential energy stored energy
“Waterfall” by narcah is licensed under CC BY 2.0

Why is potential energy stored energy

Potential energy is an energy, which exists because of the mutual interaction between two or more systems. The energy possessed by the body or system due to its position or configuration, or arrangement is called potential energy.

Conservation of energy, a universal law, states that energy neither be created nor destroyed; only its form is changed.

Suppose, if you try to lift an object to a certain height, let’s say “h” meter from the ground. Now for lifting the body, you need to do work on it. Work done on the system is given by

Work done= force*displacement

In simple words, you are displacing the object against the gravitational field. Now, this work done on an object is stored.

Now, where has this energy gone? It must have transformed as per the energy conservation law. See, you’ve lifted that body, now if you’ll allow it to fall from the same height. It will be in motion, i.e. it will have kinetic energy.

Before lifting it, the body didn’t have kinetic energy, but it possessed the energy as soon as it reached the height “h”. The work that we did in lifting was stored in energy. The stored form of energy here is gravitational potential energy

Frequently asked questions: FAQs

What is the relationship between kinetic energy and potential energy?

As we know, kinetic energy depends upon the motion and potential energy is due to the state or position of the body.

The primary relationship between these two forms of energy is that it continuously transforms into each other.

It can be easily seen by the example of a hammer. A hammer kept on the table possesses some potential energy. If the hammer is released from the table, it hits the ground. Here, the potential energy (i.e. hammer on table) is transformed into kinetic energy (i.e. hammer is released).

Give some examples of potential energy.

A ripe fruit: the ripe fruit has gravitational potential energy when it is suspended on the tree. Soon the stored energy will be available when it disconnects from the branch of the tree.

Battery: Battery has electrostatic potential energy. As soon as the battery is connected to the circuit. The chemical energy (in battery) is converted into the electrical energy (current).

Bullet: As the bullet is fired from the gun, the bullet hits the target with greater velocity. As we know, the resting bullet has stored some energy that is being transformed into kinetic energy when fired.

is potential energy stored energy
Is potential energy stored energy “Gun Smoke Red” by Knowles Gallery is licensed under CC BY 2.0

Bow and Arrow: when the bowstring is pulled back, the bowstring gains some energy, which is stored in its limbs. As soon as this bowstring is released, the Arrow is thrown in the air. Here, the elastic potential energy is being transferred into kinetic energy.   

is potential energy stored energy
Is potential energy stored energy “Hobby Archer” by pasukaru76 is marked with CC0 1.0

Pendulum: A pendulum is a system consisting of bob and string. It contains maximum potential energy when held at some height from one end. The bob reaches its mean position as soon as it is released, transforming the stored potential energy into kinetic energy.

Food: Remember, our mother scolds us for our eating habits and her frequent comments that you’ve not eaten properly. Therefore, you don’t have energy. Food is the source of energy. We consume food, and these foods or substances have chemical   potential energy residing in them. As the substance reaches our stomach, the bonds brakes and energy releases our body uses to do any work. We can say any atom or     molecule has potential energy inside it.

Is gravitational potential energy path independent?

Whenever friction is involved, the path matters. As we know, the Gravitational potential energy depends upon the difference between the heights. Hence, the path doesn’t matter. 

Let’s understand by taking an example. Suppose an object of mass m is raised to height h against the gravitational field.  The work done is mgh. The other identical body is raised to the same height through path ACDEB. The direction of force is normal to the displacement, for horizontal path CD and EB, therefore the work done along these paths is zero. Only in the vertical direction, the work is done. The net work done in raising the object is again mgh because AC+DE = h

is potential energy stored energy
Is potential energy stored energy

What are the formulas of potential energy?

Different types of potential energy exist, depending upon the configuration and field.

Gravitational potential energy

Where, m=mass,

g= gravitational acceleration,

h=height from the reference point.

Elastic potential energy

Where, k = spring constant,

x = distance

Potential energy of two charges

Where,q1 and q2  are the charges,

r is the distance between them

e0 is the permittivity of the free space.

Magnetic Potential energy

                                                            ­

Where, magnetic moment μ

B = magnetic field intensity

The unit of potential energy is Joule. 

Is sound energy potential or kinetic?

Sound energy can be considered both form of energy, kinetic and potential.

Sound energy is transmitted in a medium through compression and rarefaction. When compression occurs, the medium comes to rest, which means there is no kinetic energy.  And when rarefaction occurs, the stored potential energy (in medium) is released in the form of kinetic energy.


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