Question 399: Gravitation

Question

The work done to raise a mass m from the surface of the earth to a height h, which is equal to the radius of the earth, is :

Accepted Answer

Initial potential energy at Earths
surface is
U
i
= $$ - {{GMm} \over R}$$
Final potential energy at height h = R :
U
f
= $$ - {{GMm} \over 2R}$$
work done = change in PE
w = U
f
- U
i
= $${{GMm} \over 2R}$$
= $${{g{R^2}m} \over {2R}}$$
= $${1 \over 2}$$mgR

Answer

mgR

Answer

2mgR

Answer

$${1 \over 2}$$mgR

Answer

$${3 \over 2}$$mgR

Gravitation

The work done to raise a mass m from the surface of the earth to a height h, which is equal to the radius of the earth, is :

Choose the correct answer: