Q. Potential energy of a satellite having mass $'m'$ and rotating at a height of $6.4 \times 10^{6}m$ from the earth surface is
A) $- 0.5\ mgR_{e}$
B) $- mgR_{e}$
C) $- 2\ mgR_{e}$
D) $4\ mgR_{e}$
Explanation
(a) Potential energy $= \frac{- GMm}{r} = \frac{GMm}{R_{e} + h} = \frac{- GMm}{2R_{e}}$
$= - \frac{gR_{e}^{2}m}{2R_{e}} = - \frac{1}{2}mgR_{e} = - 0.5mgR_{e}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.