# A wind-up toy car is released and moves across a flat floor until it stops. Describe the energy transfers that occur from the moment the spring is fully wound to the moment the car comes to rest, naming the energy stores involved at each stage.

> Pearson Edexcel International GCSE Physics (4PH1) — 4.1 Energy transfers · Describe · 4 marks

> A child winds up a small toy car by turning a key, which compresses a spring inside the car. When released, the car moves across a flat floor and gradually slows to a stop.

## Mark scheme (4 marks)

1. The wound spring stores elastic potential energy
2. Elastic potential energy is transferred to kinetic energy (as the spring unwinds and the car moves)
3. As the car slows, kinetic energy is transferred to thermal energy (due to friction between the wheels/axle and surfaces)
4. The total energy is conserved throughout / no energy is created or destroyed (energy is dissipated to the surroundings as thermal energy)

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