Unit 3 - Week 4 Revision

if two objects labelled B and C are both at thermal equilibrium with object A, which of the following must be true?

• Objects B and C are in thermal equilibrium with each other

• Object B has a higher temperature than object C

• Object C has a higher temperature than object B

• Objects B and C are not in thermal equilibrium with each other

Which of the following is true about the melting of ice?

• Energy is required to increase the average kinetic energy of the water molecules

• Energy is required to decrease the average kinetic energy of the water molecules

• Energy is required to increase the potential energy between the water molecules

• No energy is required for this process as it happens spontaneously

In the image, the lines represent beakers containing either 100mL or 200mL of water heated on the same hot plate. Which line is the 100mL beaker?

• Line A

• Line B

• Impossible to determine from this image

• Both lines contain the same volume of water

The heat energy required to change 1 kg of a substance from a liquid to a gaseous state at the same temperature is called:

• Latent heat of fusion

• Latent heat of vaporisation

• Specific heat capacity

• Evaporation energy

A piece of copper is heated past the melting point. In the graph at which stage(s) is there an increase in the internal energy of the copper?

• P and R only

• P, Q, and R

• Q and R only

• Q only

A block of iron with a mass of 10kg and temperature of 10°C is brought into contact with a block of iron with mass 20 kg and temperature of 70°C. Energy transfer only happens between the blocks. What is the final temperature?

• 60

• 40

• 50

• 30

The graph shows the change in temperature for a solid as it is heated and becomes a liquid. Which phase has the greater specific heat capacity?

• Solid

• Liquid

• Neither, they are the same

• Cannot be determined from this graph

Three measurements are taken for time to heat up a mass of water, 128s, 130s, 132s. Calculate the absolute uncertainty correct to 1 d.p.

Three measurements are taken for time to heat up a mass of water, 128s, 130s, 132s. Calculate the percentage uncertainty rounded to 2 d.p. Give your answer as a percentage with symbol.