# A cyclist rides along a flat road at a constant speed. The cyclist then stops pedalling but continues to slow down until coming to rest. Explain why the cyclist slows down and describe what happens to the kinetic energy of the cyclist as they come to rest.

> Edexcel A-Level Physics (9PH0) — 8.1 Particle accelerators and detectors · Explain · 5 marks

> A cyclist travelling at a steady speed on a flat road stops pedalling. The cyclist gradually decelerates and eventually stops.

## Mark scheme (5 marks)

1. A resistive force (friction / air resistance) acts on the cyclist opposing their motion
2. The cyclist does work against the resistive force
3. The kinetic energy of the cyclist decreases / is transferred away as the cyclist slows down
4. The kinetic energy is dissipated as thermal (heat) energy to the surroundings
5. When the cyclist is at rest, all kinetic energy has been transferred / kinetic energy is zero

## Key terms

- [kinetic energy](https://www.gradenine.co.uk/glossary/kinetic-energy)

## Related

- [Revision notes for Edexcel A-Level Physics (9PH0)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-cyclist-rides-along-a-flat-4b63d5d8) · Published by Druglandscape Ltd.