# A delivery van travels along a straight road at 20 m/s. The driver sees an obstacle ahead and reacts before applying the brakes. The van then decelerates uniformly and comes to a complete stop. Explain how the concepts of thinking distance, braking distance, and stopping distance are related to this journey, and describe one factor that would increase the thinking distance in this situation.

> Edexcel A-Level Physics (9PH0) — 2.1 Motion · Explain · 5 marks

> A delivery van travels along a straight road at 20 m/s. The driver sees an obstacle ahead and reacts before applying the brakes. The van then decelerates uniformly and comes to a complete stop.

## Mark scheme (5 marks)

1. Thinking distance is the distance the van travels during the driver's reaction time (before brakes are applied)
2. Braking distance is the distance the van travels after the brakes are applied until it stops
3. Stopping distance = thinking distance + braking distance
4. One factor that increases thinking distance correctly identified (e.g. driver is tired / distracted / under the influence of alcohol or drugs)
5. Correct explanation of why the identified factor increases thinking distance — links factor to a longer reaction time, meaning the van travels further before braking begins

## Key terms

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

## 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-delivery-van-travels-along-a-26911bed) · Published by Druglandscape Ltd.