A cooling system transfers energy continuously from a 0.80 kg pure aluminium casting.
The aluminium is molten at 0 minutes.
The table shows how the temperature of the casting changes.
| Time in minutes | Temperature in ∘C^{\circ}\text{C}∘C |
|---|---|
| 0 | 720 |
| 2 | 660 |
| 4 | 660 |
| 6 | 660 |
| 8 | 660 |
| 10 | 660 |
| 12 | 620 |
| 14 | 580 |
| 16 | 540 |
Calculate the average rate of cooling during the first 2 minutes and between 10 minutes and 16 minutes. Compare the two rates.
The specific heat capacity of solid aluminium is 900 J/kg ∘C900\ \text{J/kg}\,^{\circ}\text{C}900 J/kg∘C.
Calculate the average rate at which energy is transferred from the casting between 12 minutes and 16 minutes.
The cooling system continues to transfer energy from the casting at the same rate after 16 minutes.
Calculate the energy transferred from the casting between 16 minutes and 19 minutes and the temperature of the casting at 19 minutes.
Explain why the temperature of the casting stays constant during the period when the table shows no temperature change, even though energy is transferred from it.
110 exam-style questions on Edexcel GCSE Physics 14.2 Specific heat capacity and latent heat, covering 14.2.1 Heating, temperature and changes of state, 14.2.2 Specific heat capacity and specific latent heat, 14.2.3 Specific heat capacity calculation, 14.2.4 Specific latent heat calculation, and 14.2.5 Reducing energy transfer through thermal insulation. Each one has a worked solution and a mark scheme showing where the marks go.