# A car is travelling at high speed along a motorway when the driver notices a hazard ahead and applies the brakes. The car comes to a complete stop. Explain how the thinking distance and the braking distance each contribute to the total stopping distance, and describe TWO factors — one that affects thinking distance and one that affects braking distance — that could increase the total stopping distance.

> WJEC A-Level Physics (Wales) — 4.2 Kinetic theory and gases (A-Level only) · Explain · 5 marks

## Mark scheme (5 marks)

1. Stopping distance is the sum of thinking distance and braking distance
2. Thinking distance is the distance the car travels during the driver's reaction time
3. Braking distance is the distance the car travels under the braking force (after brakes are applied until the car stops)
4. A named factor that increases thinking distance — e.g. tiredness, alcohol, or drugs (increasing reaction time)
5. A named factor that increases braking distance — e.g. adverse road/weather conditions (e.g. wet or icy roads) or poor vehicle condition (e.g. worn brakes or worn tyres)

## Key terms

- [stopping distance](https://www.gradenine.co.uk/glossary/stopping-distance)
- [thinking distance](https://www.gradenine.co.uk/glossary/thinking-distance)
- [braking distance](https://www.gradenine.co.uk/glossary/braking-distance)

## Related

- [Revision notes for WJEC A-Level Physics (Wales)](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-car-is-travelling-at-high-e84b84b9) · Published by Druglandscape Ltd.