Answer: Equator.
- A North Pole
- B Equator
- C Tropic of Cancer
- D Any latitude
Correct answer: B. Equator
Explanation: A geostationary orbit must be directly over the equator with zero inclination to remain fixed over one point.
g is maximum at Earth's surface; going up, it falls off as 1/r² (inverse-square); going down, it falls off linearly with depth (since only the mass enclosed within radius r contributes), reaching zero at the centre.
Concept context
Universal gravitation, orbital mechanics, gravitational potential, and escape velocity.