Physics - Gravitation Question with Solution | TestHub

If a point mass m is placed at a height h from surface of earth, the potential energy is $U_h=-\frac{GMm}{(R+h)}=\frac{-g{R}^{2}m}{R\left(1+\frac{h}{R}\right)}=\frac{-g{R}^{2}m}{R}{\left(1+\frac{h}{R}\right)}^{-1}$$\left(\because g=\frac{GM}{R^2}\right)$ $U_h=\frac{-g{R}^{2}m(R-h)}{R^2}$ $=-gm(R-h)$ $\therefore V=\frac{U_h}{m}=\frac{-gm(R-h)}{m}=-g(R-h)$