Answer: 6.67 x 10-11 N m2/kg2.
- A 6.67 x 10-11 N m2/kg2
- B 9.8 m/s2
- C 6.67 x 10-11 N/m2
- D 9.8 N/kg2
Correct answer: A. 6.67 x 10-11 N m2/kg2
Explanation: G = 6.674 x 10-11 N m2 kg-2 (Universal Gravitational Constant).
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.