A natural satellite moves around a planet in a repeating orbit. Observations are made as the satellite moves from P to Q and then towards R.
| Position | Distance from the centre of the planet in km | Speed in km/s |
|---|---|---|
| P | 84 000 | 1.00 |
| Q | 78 000 | 1.10 |
| R | 72 000 | not measured |
Describe what the observations at P and Q show about the shape of the orbit and the change in the speed of the satellite.
Predict how the speed of the satellite and the gravitational pull on it at R compare with those at Q.
Explain your predictions.
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.