Question

How much energy is required to move a stationary body of mass M from an orbit of radius 2R to 3R?
$Hint:U=U_1-U_1$

Answer 1

Potential is given by

$V=-\frac{GmM}{r}$

Here, the body is orbiting from 2R to 3R

$V=\frac{-GmM}{3R}-\left(\frac{-GmM}{2R}\right)$

$V=\frac{GmM}{6R}$