The energy required to move an earth satellites of mass m from a circular orbit of radius 2 R to a radius 3 R is `" "` (R is radius of the earth)

Options

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

Answer

c

Explanation

`E(2)-E_(1)=-(GMm)/(2r_(2))+(GMm)/(2r_(1))`
`=-(GMm)/(6R)+(GMm)/(4R)`
`=(GMm)/(2R)((1)/(2)-(1)/(3))=(GMm)/(12R)`.