Specific Heat Capacity - Part 1

Specific Heat Capacity - Part 1

PHYSIC FORM 4 KSSM SMKAI

Have you have an experienced like shown in the picture. Think, and choose the best answer in next slide.

Multiple Choice

The sun heats up the sand and sea water at the same period of time. Which is the correct observation from the situation given?

• sand gets hot slowly and sea water gets hot quickly

• sand gets hot quickly and sea water gets hot slowly

• both gets hot in a same time.

By exposing different objects with same amount of heat, does not make object heats up equally in a same time.  Different objects have different heat capacity. Remember on the first picture? Sand has a low heat capacity and gets hot quickly while sea water has a high heat capacity and gets hot slowly.

Heat capacity, C

Heat capacity, C of an object is the quantity of heat needed to raise the temperature of the object by 1°C.

Q = quantity of heat supplied

Δθ = change in temperature

Unit for C = J °C–1

Multiple Choice

"When 100 J of heat is supplied to objects X and Y, object X experiences a rise in temperature of 1°C and object Y 2°C. "

Based on the statement above, which objects have higher heat capacity?

• X

• Y

Multiple Choice

When 100 J of heat is supplied to objects X and Y, object X experiences a rise in temperature of 1°C and object Y 2°C. This is due to object have different heat capacity. Based on below, which of the best assumptions on "object X have high heat capacity"

• Rise of temperature in object X is bigger.

• Rise of temperature in object X is smaller

Physics is about quantity!!!

When 100 J of heat is supplied to objects X and Y, object X experiences a rise in temperature of 1°C and object Y 2°C. What are the respective heat capacity of objects X and Y?

Look at the diagram given, caculate, use the formula given. Then, you may use the answer to identify which object has high heat capacity.

Memorize this!!!!

"The temperature increase is small if the object has a high heat capacity."

Multiple Choice

When 100 J of heat is supplied to objects W, X , Y and Z, object W experiences a rise in temperature of 4°C , object X =1°C, object Y = 3 °C and Z = 2°C. Arrange the object in ascending order according to their heat capacity.

• W, X, Y, Z

• Z, W, Y, X

• Y, X, W, Z

• X, Z, Y, V

Multiple Choice

When 500 J of heat is supplied to objects M, N and O, object M experiences a rise in temperature of 5°C, object N= 3°C and object O = 7 °C. Which object has higher heat capacity?

• M

• N

• O

Multiple Choice

When 500 J of heat is supplied to objects M, N and O, object M experiences a rise in temperature of 5°C, object N= 3°C and object O = 7 °C. Which object has smaller heat capacity?

• M

• N

• O

Heat capactiy

Observe the diagram given. Both object heated by immersion heater with 12 000 J of energy for 5 minutes. Which object do you think will have higher temperature increase?

Multiple Choice

If the water in beaker A and beaker B is heated for 5 minutes using the same Bunsen burner, which water in the beaker will show higher temperature?

• A

• B

The relationship between the mass of the material and the heat capacity

Heat capacity of an object increases when the mass of the object increases. For example, the water in a full kettle takes a longer time to boil compared to the water in a half-filled kettle. Th is shows that water of bigger mass has a higher heat capacity compared to water of smaller mass. 

Specific Heat Capacity of Substance

A material engineer tries to choose a suitable metal as building material. He needs a material that does not heat up easily. Since the heat capacity of a material differs with its mass, he needs to make his choice based on specific heat capacity instead – which means he has to choose the material based on the heat capacity of every 1 kg of each material.

For example, the specifi c heat capacity of the metal aluminium is 900 J kg–1 °C–1. Th is means 1 kg of aluminium requires 900 J of heat to raise its temperature by 1°C.

Specifi c Heat Capacity of Substance

• What does the specific heat capacity of aluminium

  = 900 J kg^-1°C^-1

  900 J heat required by 1 kg of aluminum to raise the temperature by 1 ° C.

  
  

  
  

  
  

• What does the specific heat capacity of water mean?

  =4200 J kg^-1°C^-1

Multiple Choice

What does the specific heat capacity of water mean?

=4200 J kg^-1°C^-1

• 4200 J heat required by 1 kg of water to raise the temperature by 2 ° C

• 4200 J heat required by 2 kg of water to raise the temperature by 1 ° C

• 4200 J heat required by 1 kg of water to raise the temperature by 1 ° C

Congratulations.

Hope you are understand on the concept of heat capacity.