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

Explanation

Gravitational P.E. of mass m in orbit of radius `R=U = -(GMm)/(R )`
`U_i= -(GMm)/(2R)`
`U_f= -(GMm)/(3R)`
`triangleU=U_(f) -U_(i)=GMm[(1)/(2)-(1)/(3)]` `=(GMm)/(6R)`.