Q. The kinetic energy needed to project a body of mass $m$ from the earth surface (radius $R$) to infinity is
A) $mgR/2$
B) $2\ mgR$
C) $mgR$
D) $mgR/4$
Explanation
(c) $\frac{1}{2}mv_{e}^{2} = \frac{1}{2}m\ 2gR = mgR$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.