Class 11 NEET Physics Gravitation Questions

Gravitational potential energy at any point at a distance r from the centre of the earth is
U=−

GMm

r

where M and m be masses of the earth and the body respectively. At the surface of the earth, r = R
∴Ui=−

GMm

R

At height h from the surface,
r=R+h=R+2R  ∵h=2R(Given)
=3R
∴Uf=−

GMm

3R

Change in potential energy,
ΔU=Uf−Ui