# A cyclist rides along a flat road at a constant speed. Explain why the cyclist must keep pedalling to maintain this constant speed, and describe what happens to the energy that is not used to keep the cyclist moving forward.

> Edexcel GCSE Physics (1PH0) — 8.1 Energy — forces doing work · Explain · 4 marks

> A cyclist travels along a flat road at a constant speed. Despite the road being flat and the speed not changing, the cyclist must continue to apply a force by pedalling.

## Mark scheme (4 marks)

1. There is a resistive force (such as friction / air resistance) acting against the cyclist's motion
2. The cyclist must do work to overcome this resistive force / the driving force must equal the resistive force to maintain constant speed
3. Energy is dissipated / transferred to the surroundings
4. The dissipated energy is transferred as heat (thermal energy), causing a rise in temperature of the surroundings / the cyclist's body / the tyres

## Related

- [Revision notes for Edexcel GCSE Physics (1PH0)](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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