# A student wants to estimate the kinetic energy of a cyclist travelling along a flat road. Explain how the student could arrive at a reasonable estimate, giving a final value with a unit.

> AQA A-Level Physics (7408) — 3.1.3 Estimation of Physical Quantities · Explain · 5 marks

## Mark scheme (5 marks)

1. Recall or estimate the mass of a cyclist (including the bicycle) in a reasonable range, e.g. 70–100 kg
2. Recall or estimate the speed of a cyclist in a reasonable range, e.g. 5–15 m/s (or converts a reasonable mph value correctly)
3. States the equation for kinetic energy: KE = ½mv²
4. Substitutes their estimated values correctly into the equation
5. Gives a final answer consistent with their values and in joules (J)

## Key terms

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

## Related

- [Revision notes for AQA A-Level Physics (7408)](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-student-wants-to-estimate-the-04cbd911) · Published by Druglandscape Ltd.