# A bungee jumper leaps from a bridge. At the moment of jumping, the jumper accelerates downwards rapidly. As the bungee cord stretches, the jumper eventually reaches a point where they move at a constant velocity before the cord pulls them back upwards. Explain why the jumper first accelerates and then reaches a constant velocity during the downward descent.

> OCR GCSE Physics A: Gateway Science (J249) — P2.3 Forces in action · Explain · 4 marks

> A bungee cord is an elastic cord that stretches when a force is applied to it. As the jumper falls, the cord begins to stretch and exerts an increasing upward force on the jumper.

## Mark scheme (4 marks)

1. At the moment of jumping, the only significant downward force is the jumper's weight / gravitational force
2. The resultant force is downwards so the jumper accelerates downwards (Newton's First / Second Law)
3. As the cord stretches, the upward (elastic / tension) force from the cord increases
4. Constant velocity is reached when the upward force from the cord equals the downward weight, giving a resultant force of zero / balanced forces

## Key terms

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

## Related

- [Revision notes for OCR GCSE Physics A: Gateway Science (J249)](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-bungee-jumper-leaps-from-a-cbb00230) · Published by Druglandscape Ltd.