Orbital speeds of planets and satellites
2 marks · EasyThe following table shows orbital radii and periods for two satellites orbiting the same planet.
| Satellite | Orbital radius (1000 km) | Period (h) |
|---|---|---|
| X | 15 | 7 |
| Y | 30 | 28 |
Which satellite orbits closer to the planet? Support your answer using data from the table.
Explain which satellite has the greater orbital speed.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) Satellite X. It has a smaller orbital radius (15,000 km vs 30,000 km).
(b) Satellite X, since satellites closer to the planet travel faster.
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Correctly identifies Satellite X and uses orbital radius.
B2 (b) · 1 mark · Explains that satellites in lower orbits have greater speed.
Worked solution
a) Satellite X is closer because it has the smaller orbital radius. b) Satellite X has higher speed as closer satellites move faster to stay in orbit.