# Explain why an astronaut's weight changes when they travel from the surface of the Earth to the surface of the Moon, but their mass does not change.

> AQA A-Level Physics (7408) — 3.7.2 Gravitational Fields · Explain · 5 marks

> The Moon has a smaller gravitational field strength than the Earth. The gravitational field strength on Earth is approximately 10 N/kg and on the Moon it is approximately 1.6 N/kg.

## Mark scheme (5 marks)

1. Mass is the amount of matter in an object
2. Mass does not depend on location / mass is the same everywhere / mass is not affected by gravitational field strength
3. Weight is the force of gravity acting on an object
4. Weight depends on gravitational field strength (W = mg)
5. The gravitational field strength on the Moon is less than on Earth, so the astronaut's weight is less on the Moon

## Key terms

- [mass](https://www.gradenine.co.uk/glossary/mass)
- [weight](https://www.gradenine.co.uk/glossary/weight)

## Related

- [Revision notes for AQA A-Level Physics (7408)](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/explain-why-an-astronaut-s-weight-changes-11aeff3e) · Published by Druglandscape Ltd.