A trolley is released from rest at the top of a ramp and rolls to the bottom. The trolley, the ramp and the air around them can be treated as a closed system. The table shows the energy in the trolley's stores, and the energy transferred to thermal stores, at three positions.
| Position | Gravitational potential store of trolley in J | Kinetic store of trolley in J | Energy transferred to thermal stores of trolley, ramp and air in J |
|---|---|---|---|
| Top | 12.0 | 0.0 | 0.0 |
| Halfway down | 6.0 | 5.4 | 0.6 |
| Bottom | 0.0 | 10.8 | 1.2 |
Explain how the data show that energy is conserved as the trolley rolls down the ramp.
104 exam-style questions on AQA GCSE Physics 1.2 Conservation and dissipation of energy, covering 1.2.1 Energy transfers in a system and 1.2.2 Efficiency. Each one has a worked solution and a mark scheme showing where the marks go.