# 11+ Thermal Equilibrium Example: Detailed Explanations

In this article “Thermal equilibrium example” will be discuss with detailed explanations. Thermal equilibrium example is very important concept to understand the changing of state for a substance.

11+ Thermal Equilibrium Example is encounter in below,

## Refrigerator:-

Refrigerator is a device which is appropriate example of thermal expansion. When a food item is stored in the refrigerator that time the item will start to goes down its temperature and the temperature of the refrigerator and the temperature of food item will be same and the process of temperature changing for the food item will be stop.

Refrigerator is a home appliance and commercial appliance. The refrigerator carry a compartment with thermal insulator and also a heat pump through which heat easily can transfer from its midst to its external surrounding. For this process the inside temperature of the refrigerator will be lower than the temperature of the room.

## Oven:-

Oven is a device which is also an appropriate example of thermal expansion. When a food item is placed in an oven and heat is applied on it that time the item will start to goes up its temperature. When the temperature of the oven and the temperature of food item will be same that time the process of temperature changing between the oven and the food item will be stop.

An oven is use for cooking purpose and also heats the food item to a wished temperature.

### Types of oven:

Types of oven is listed below,

1. Electric oven
2. Gas oven
3. Earth oven
4. Masonry oven
5. Toaster oven
6. Ceramic oven
7. Wall oven
8. Steam oven
9. Microwave oven

## Melting of a ice cube:-

Another example of thermal expansion is melting of an ice cube. When an ice cube placed on a normal temperature its try to reaching at the room temperature and melting point will be increases at this particular time ice cube start to changing its state from solid to liquid.

## Freezing of water:-

Another example of thermal expansion is freezing of water. When water is placed on a lower temperature its try to reaching at the lower temperature from the normal temperature at this particular time water starts to change its state from liquid to solid.

## Drying of wet hair:-

Drying of wet hair is another regular example of thermal expansion. When we dry our wet hair in normal room temperature that time our wet hair reach at the room temperature and hair will be dry.

## Drying of wet clothes:-

Drying of wet clothes is another regular example of thermal expansion. When we dry our wet clothes in normal room temperature that time our wet clothes reach at the room temperature and cloth will be dry.

## Cooling of a cup of tea:-

Cooling of a cup of tea is another regular example of thermal expansion. When a cup of tea is placed on a normal room temperature that time a cup of tea try to reaching at the room temperature and boiling point will be decreases. A cup of tea starts to change its temperature and became cool.

## Melting of ice-cream:-

Another example of thermal expansion is melting of ice cream. When ice cream is placed on a normal room temperature that time its try to reaching at the room temperature and melting point will be increases and freezing point will be decreases. The ice cream starts to change its state from solid to liquid.

## Freezing of ice- cream:-

Another example of thermal expansion is freezing of ice cream. When ice cream is placed on a refrigerator that time ice cream try to reaching at the refrigerant temperature and melting point will be decreases and freezing point will be increases. For this particular reason the ice cream starts to change its state from liquid to solid.

## Cooling of a hot rod:-

Cooling of a hot rod is another example of thermal expansion. When a rod has higher temperature after doing any operation it became hotter. When a hotter rod is placed in a normal room temperature that time the rod try to reach at the room temperature. The rod starts to decreases its temperature and became cool.

## Making of tea:-

When we make tea that time with hot water milk is added at that time the temperature of milk is low and the temperature of water is cold but when hot water and cold milk is added to each the mixture comes in a normal temperature. So, making of tea is also another example of thermal expansion.

## Question: –

### Write the formula for thermal equilibrium.

Solution: – When two different matters stay in same temperature that’s mean the two different matters maintain thermal equilibrium.

The formula for thermal equilibrium is,

$Q = m * C_e * \Delta t$

Where,

Q = Total energy of the specific matter of the body which is expressed in Joule

m = Mass of the specific matter of the body which is expressed in grams

$C_e$ = Specific heat of the specific matter of the body which is expressed in joule per Kelvin per kilogram

$\Delta t$ = (Final temperature – Starting temperature) of the specific matter of the body which is expressed in Kelvin

## Question: –

### Find the exact temperature where the temperature of the aluminium and the temperature of the water will be same.

Solution: –

We know that,

$Q = m * C_e * \Delta t$

Where,

Q = Total energy of the specific matter of the body

m = Mass of the specific matter of the body

$C_e$ = Specific heat of the specific matter of the body

$\Delta t$ = (Final temperature – Starting temperature) of the specific matter of the body

For aluminium,

$Q_A = m_A * C_e_A * \Delta t_A………….. eqn (1)$

Given data are,

$m_A$ =  15 gram

$C_e_A$  = 0.215 calorie per gram degree centigrade

$\Delta t_A$ = $(T_f – T_i_A) degree centigrade = (T_f – 39) degree centigrade$

For water,

$Q_W = m_W * C_e_W * \Delta t_W………….. eqn (1)$

Given data are,

$m_W$ = 32 gram

$C_e_W$ = 1 calorie per gram degree centigrade

$\Delta t_W = (T_f – T_i_W) degree centigrade = (T_f – 20) degree centigrade$

Now, from………….. eqn (1) and ………….. eqn (2) we can write,

$Q_A = m_A * C_e_A * \Delta t_A = (-) Q_W = (-) m_W * C_e_W * \Delta t_W$

Putting the value from eqn (1) and eqn (2),

$15 \times (0.215) \times (T_f – 39) = (-) 32 \times 1 \times (T_f – 20)$

(Put the value for $C_e_W$ = 1 calorie per gram degree centigrade)

$3.225 \times (T_f – 39) = -32 (T_f – 20)$

$3.225 T_f – 125.775 = -32 T_f + 640$

$3.225 T_f + 32 T_f = 640 + 125.775$

$T_f = \frac{640 + 125.775}{35.225}$

$T_f$ = 21.7 degree centigrade

In a house a bowl is present which is decorated with beautiful stones. The bowl is made with aluminium. The weight of the bowl is 15 gram and temperature is about 39 degree centigrade. Now in the aluminium bowl water is placed. At this condition the temperature of the water will be 20 degree centigrade and weight of the water is about 32 gram

The exact temperature where the temperature of the aluminium and the temperature of the water will be same is 21.7 degree centigrade

## Question: –

### Explain types of thermodynamic equilibrium.

Solution: – A system is called thermodynamic equilibrium when mechanical equilibrium, thermal equilibrium and chemical equilibrium are same.

Thermodynamic equilibrium three types, they are,

### Mechanical equilibrium:-

A system is called mechanical equilibrium when pressure will be no changed in any condition and also no changes in acting of unbalanced force.

### Thermal equilibrium:-

A system is called thermal equilibrium when temperature will be no changed in any condition inside the system of the matter.

### Chemical equilibrium:-

A system is called chemical equilibrium when chemical reaction no present inside the system and also any type of composition changes is not present of the matter.

Indrani Banerjee

Hi..I am Indrani Banerjee. I completed my bachelor's degree in mechanical engineering. I am a enthusiastic person and I am a person who is positive about every aspect of life. I like to read Books and listening to music.