Gravitation Question 126
Question: If mass of earth is M, radius is R and gravitational constant is G, then work done to take 1 kg mass from earth surface to infinity will be [RPET 1997]
Options:
A) $ [\sqrt{\frac{GM}{2R}}] $
B) $ [\frac{GM}{R}] $
C) $ [\sqrt{\frac{2GM}{R}}] $
D) $ [\frac{GM}{2R}] $
Show Answer
Answer:
Correct Answer: B
Solution:
Potential energy of the 1 kg mass which is placed at the earth surface = $ [-\frac{GM}{R}] $ its potential energy at infinite = 0 Work done = change in potential energy = $ [\frac{GM}{R}] $
