Answer: Increase by sqrt(2).
- A Halve under typical conditions
- B Stay same according to standard textbooks
- C Increase by sqrt(2)
- D Double in general practice
Correct answer: C. Increase by sqrt(2)
Explanation: ve = sqrt(2GM/R). If M doubles, ve = sqrt(2 x 2GM/R) = sqrt(2) x original ve.
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.