The Table shows the orbital radius and orbital speed of four satellites, A, B, C and D. Each satellite is in a stable circular orbit around the Earth.
Table
| Satellite | Orbital radius in km\text{km}km | Orbital speed in km/s\text{km/s}km/s |
|---|---|---|
| A | 6700 | 7.7 |
| B | 7000 | 7.5 |
| C | 26 60026\ 60026 600 | 3.9 |
| D | 42 20042\ 20042 200 | 3.1 |
Describe how the orbital speed of a satellite depends on its orbital radius.
Satellite D is in a geostationary orbit.
The circumference of a circle =2π×radius= 2\pi \times \text{radius}=2π×radius
Show that satellite D takes about 24 hours to complete one orbit.
Explain why satellite A must move faster than satellite D to stay in a stable orbit.
50 exam-style questions on OCR GCSE Physics 8.3 Beyond Earth, covering 8.3.1 Red-shift and the expanding universe, 8.3.2 Evidence for the Big Bang model, 8.3.3 Formation of the Sun and stellar equilibrium, 8.3.4 Radiation emitted by hot bodies, 8.3.5 The solar system and satellites, 8.3.6 Gravity and circular orbits, 8.3.7 Orbital radius and orbital speed, 8.3.8 Radiation balance and the temperature of the Earth, and 8.3.9 Seismic waves and exploring hidden structures. Each one has a worked solution and a mark scheme showing where the marks go.