# Explain why planets that are further from the Sun take longer to complete one orbit than planets that are closer to the Sun.

> Eduqas GCSE Physics — 10.1 Solar system; stability of orbital motions; satellites · Explain · 4 marks

## Mark scheme (4 marks)

1. Gravitational force/pull from the Sun is weaker at greater distances
2. A weaker gravitational force means the orbital speed of the planet is lower/slower
3. A planet further from the Sun has a larger orbit / travels a greater distance in one orbit
4. Both a lower speed and a greater distance to travel combine to make the orbital period longer

## Key terms

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

## Related

- [Revision notes for Eduqas GCSE Physics](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-planets-that-are-further-da8807ba) · Published by Druglandscape Ltd.