AQA ยท GCSE Physics

Phase-change thermal storage GCSE Physics challenge

Can you get 100%? Use a real thermal-energy storage design to test internal energy, melting, conduction and convection in one original GCSE Physics question.

Read how fins improve thermal energy storage

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Question

7 marks

Answer all four parts. Use particle and energy ideas in your explanations.

1(a)

A phase-change thermal store contains a material that melts as it absorbs energy. State what is meant by the internal energy of the material.

[1 mark]

1(b)

The material continues to absorb energy while it melts, but its temperature remains approximately constant. Explain how its internal energy can increase without an increase in temperature.

[2 marks]

1(c)

Metal fins extend from a hot pipe into the phase-change material. Explain two ways in which the fins can make the solid material melt faster.

[2 marks]

1(d)

Once some material has melted, warmer liquid rises and cooler liquid sinks in the gaps between the fins. Simulations found that fins placed too close together could slow the overall melting. Explain both observations.

[2 marks]

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