# A cyclist rides along a straight, flat road. She accelerates from rest, travels at a constant speed, and then decelerates to a stop. Describe how the distance travelled by the cyclist changes over time during each of the three stages of her journey, and explain what the motion tells us about the forces acting on the cyclist during the constant speed stage.

> OCR A-Level Physics B: Advancing Physics (H557) — 3.1 Motion · Describe · 5 marks

> A cyclist starts from rest at a set of traffic lights. She accelerates steadily, then maintains a constant speed for several seconds, before braking to a stop at the next set of traffic lights.

## Mark scheme (5 marks)

1. During acceleration, the distance travelled increases at a faster and faster rate (distance–time relationship is curved/getting steeper).
2. During constant speed, distance increases at a steady/uniform rate (equal distance covered in equal time intervals).
3. During deceleration, the distance travelled still increases but at a slower and slower rate (gradient decreases / curves and flattens).
4. At constant speed the resultant force on the cyclist is zero.
5. At constant speed the driving/forward force from the cyclist equals the resistive forces (such as friction/air resistance/drag) acting on her.

## Key terms

- [constant speed](https://www.gradenine.co.uk/glossary/constant-speed)

## Related

- [Revision notes for OCR A-Level Physics B: Advancing Physics (H557)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" 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-straight-e6ef5dbd) · Published by Druglandscape Ltd.