Two satellites move in circular orbits around the same planet. The table gives their orbital radii and periods.
| Satellite | Orbital radius in km\mathrm{km}km | Orbital period in h\mathrm{h}h |
|---|---|---|
| P | 8000 | 2.0 |
| Q | 32 00032\,00032000 | 16 |
Use orbital speed=2πrT\text{orbital speed}=\dfrac{2\pi r}{T}orbital speed=T2πr.
What is the ratio of the speed of P to the speed of Q?
2:12:12:1
1:21:21:2
1:81:81:8
8:18:18:1
80 exam-style questions on Edexcel GCSE Physics 7.1 The Solar System and gravity, covering 7.1.1 Weight and g on different bodies in space, 7.1.2 The Solar System, 7.1.3 Changing ideas about the Solar System, 7.1.4 Orbits of moons, planets, comets and satellites, and 7.1.5 Gravity and orbital motion. Each one has a worked solution and a mark scheme showing where the marks go.