Question 1

A continuous stream of water falls through a vertical distance of 100 m.

Assume no thermal energy is transferred to the surroundings.

The specific heat capacity of water is 4200 J kg−1 K−1.

What is the temperature difference of the water between the top and bottom of the waterfall?

  A  

0.023 K

  B  

0.23 K

  C  

2.3 K

  D  

4.3 K

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Question 2

A student measures the power of a microwave oven. He places 200 g of water at 23 °C into the microwave and heats it on full power for 1 minute. When he removes it, the temperature of the water is 79 °C.

The specific heat capacity of water is 4200 J kg−1 K−1.

What is the average rate at which thermal energy is gained by the water?

  A  

780 W

  B  

840 W

  C  

1.1 kW

  D  

4.6 kW

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Question 3

A liquid flows continuously through a chamber that contains an electric heater. When the steady state is reached, the liquid leaving the chamber is at a higher temperature than the liquid entering the chamber. The difference in temperature is Δt. 

Which of the following will increase Δt with no other change?

  A  

increasing the volume flow rate of the liquid


  B  

changing the liquid to one with a lower specific heat capacity

  C  

using a heating element with a higher resistance

  D  

changing the liquid to one that has a higher density

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Question 4

The temperature of a hot liquid in a container falls at a rate of 2 K per minute just before it begins to solidify. The temperature then remains steady for 20 minutes by which time all the liquid has all solidified.

What is the quantity specific heat capacity of the liquidSpecific latent heat of fusion\frac{specific\ heat\ capacity\ of\ the\ liquid}{Specific\ latent\ heat\ of\ fusion}? 

401​ K−1
101​ K−1
10 K−1
40 K−1

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Question 5

A solar panel transfers energy at a rate of 1.2 kW to liquid passing through it. The liquid has a specific heat capacity of 4.0 kJ kg−1 K−1.

When the liquid flows through the solar panel, its temperature increases by 3.0 K.

The flow rate of the liquid is

  A  

0.10 kg s−1

  B  

1.1 kg s−1

  C  

10 kg s−1.    

  D  

100 kg s−1

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Question 6

The latent heat of vaporisation of a liquid is 2300 kJ kg−1 and it has a molar mass of 0.018 kg mol−1.

What is the energy required to change 30 moles of the liquid to gas?

  A  

4.1 × 104 J


  B  

1.2 × 106 J


  C  

6.9 × 107 J


  D  

3.8 × 109 J


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Question 7

A metal block of mass 0.28 kg has an initial temperature of 82 °C. It is dropped into cold water. The temperature of the block after 1.2 minutes is 20 °C.

The specific heat capacity of the metal is 130 J kg−1 K−1.

What is the average thermal power transferred away from the metal block?

  A  

31 W

  B  

41 W

  C  

1,900 W

  D  

2,700 W

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Question 8

A small amount of copper is heated in a container. The copper starts to melt.

Which statement about the melting of copper is correct?

  A  

temperature is constant and the kinetic energy of the copper atoms increases.

  B  

temperature increases and the potential energy of the copper atoms increases

  C  

temperature is constant and the potential energy of the copper atoms increases

  D  

temperature increases and the kinetic energy of the copper atoms increases

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Question 9

What is the correct unit for specific heat capacity?

  A  

m2 s–2 K–1

  B  

m s–2 K–1

  C  

m2 s–1 K–1

  D  

m2 s–2 K

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Question 10

A solid molecular substance is supplied with energy and it starts to melt.

Which of the following pairs of quantities remains the same as the substance melts?

  A  

kinetic energy of molecules and internal energy of molecules


  B  

potential energy of molecules and internal energy of molecules


  C  

kinetic energy of molecules and temperature of substance

  D  

potential energy of molecules and temperature of substance

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Question 11

When ice melts, it contracts.

Which row is correct for ice turning into water?

  A  
  B  
  C  
  D  

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