# A rocket is launched vertically upwards from the ground. After the engines cut out, the rocket continues to move upwards before eventually falling back to the ground. State and explain how the speed of the rocket changes from the moment the engines cut out until the rocket reaches its highest point, and explain why the displacement of the rocket at the moment it lands is zero.

> Cambridge International IGCSE Physics (0625) — 1.2 Motion · Explain · 4 marks

## Mark scheme (4 marks)

1. The speed of the rocket decreases (after engines cut out) / the rocket decelerates
2. Because the resultant force acts downwards (due to gravity/weight) opposing the upward motion
3. Displacement is a vector quantity / displacement has both magnitude and direction
4. The rocket returns to its starting position, so its overall change in position is zero / final position equals initial position

## Key terms

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

## Related

- [Revision notes for Cambridge International IGCSE Physics (0625)](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-rocket-is-launched-vertically-upwards-2b634df0) · Published by Druglandscape Ltd.