Energy required to move a body of mass m from an orbit of radius 2R to 3R is

Options

A. `GMm//12R^(2)`
B. `GMm//3R^(2)`
C. `GMm//8R`
D. `GMm//6R`

Answer

D

Explanation

Energy required `=U_(f)-U_(i)`
`=-(GMm)/(3R)+(GMm)/(2R)=-(GMm)/(R)(-(1)/(3)+(1)/(2))`
`=(GMm)/(R)(-(2+3)/(6))=(GMm)/(6R)`