Question

Conventionally, the magnitude of gravitational potential energy for an object at infinity from the earth is _____ ((M = Mass of the earth; m = Mass of the object at infinity; R = Radius of the earth).

(a) -(G*M)/R^2

(b) -(G*M)/R

(c) -(G*M*m)/R

(d) Zero

The question was posed to me in a national level competition.

This key question is from Gravitational Potential Energy in section Gravitation of Physics – Class 11

Answer 1

The correct answer is (d) Zero

For explanation: Gravitational Potential Energy (U) = -(G*M*m)/r

At infinity, r -> infinity

Therefore, U -> 0.