Physics - Gravitation Question with Solution | TestHub

At a height h above the surface of earth the gravitational potential energy of the particle of mass m is ${\mathrm{U}}_{\mathrm{h}}=-\frac{{\mathrm{GM}}_{\mathrm{e}}\mathrm{m}}{{\mathrm{R}}_{\mathrm{e}}+\mathrm{h}}$ Where $M_e\&R_e$ are the mass $\&$ radius of earth respectively. In this question, since $\mathrm{h}={\mathrm{R}}_{\mathrm{e}}$ So $U_{h-R_e}=-\frac{G{M}_{e}m}{2R_e}=\frac{-mg{R}_e}{2}$