Q. A spherical planet has a mass Mp and diameter Dp. A particle of mass m falling freely near the surface of this planet will experience an acceleration due to gravity, equal to
A) 4GMₚm/Dₚ²
B) 4GMₚ/Dₚ²
C) GMₚm/Dₚ²
D) GMₚ/Dₚ²
Explanation
[Solution from source] g = GM/R² and R = Dₚ/2, so g = GMₚ/(Dₚ/2)² = 4GMₚ/Dₚ². Acceleration does not depend on the particle's mass m, so expressions containing m are forces, not accelerations. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.