The energy required to move a satellite of mass m from an orbit of radius 2R to 3R is (where M is the mass of the earth and R is the radius of the earth)

Options

A. `(GMm)/(12 R^(2))`
B. `(GMm)/(3R^(2))`
C. `(GMm)/(8R)`
D. `(GMm)/(4R)`

Answer

D

Explanation

Change in potential energy in displacing a body from `r_(1)` to `r_(2)` is given by
`DeltaU=GMm[(1)/(r_(1))-(1)/(r_(2))]=GMm((1)/(2R)-(1)/(4R))=(GMm)/(4R)`