# A passenger train travels between two stations. It leaves the first station from rest and accelerates uniformly. It then travels at a constant speed before decelerating uniformly to rest at the second station. Describe the motion of the train during each stage of the journey, explaining how the distance travelled during the acceleration stage compares to the distance travelled during the deceleration stage if both stages last the same amount of time but the deceleration is twice the magnitude of the acceleration.

> Edexcel GCSE Physics (1PH0) — 2.1 Motion · Describe · 4 marks

> A passenger train travels between two stations. It leaves the first station from rest and accelerates uniformly, then travels at a constant speed, before decelerating uniformly to rest at the second station. The deceleration stage lasts the same length of time as the acceleration stage, but the magnitude of the deceleration is twice the magnitude of the acceleration.

## Mark scheme (4 marks)

1. During the acceleration stage, the train's speed increases at a steady/uniform rate (velocity increases uniformly from zero).
2. During the constant speed stage, the train travels at the same speed / velocity does not change / acceleration is zero.
3. During the deceleration stage, the train's speed decreases at a steady/uniform rate (to rest).
4. The distance during acceleration is greater than the distance during deceleration, because the average speed during acceleration (starting from zero and reaching top speed) is the same as during deceleration (starting from top speed and reaching zero) — but since deceleration is twice as large, the deceleration stage takes half the time to reach zero from top speed if time were equal, meaning if time IS the same, the top speed reached during acceleration is half that during deceleration, so the train covers less distance during deceleration / OR: same time but deceleration is twice as large means the final speed drops twice as fast, so average speed over deceleration is lower, covering less distance.

## Key terms

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

## Related

- [Revision notes for Edexcel GCSE Physics (1PH0)](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-passenger-train-travels-between-two-4fe00c58) · Published by Druglandscape Ltd.