Q. The required kinetic energy of an object of mass $m,$ so that it may escape, will be
A) $\frac{1}{4}mgR$
B) $\frac{1}{2}mgR$
C) $mgR$
D) $2mgR$
Explanation
(c) $kinetic\ energy = \frac{1}{2}{mv}_{e}^{2}$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ = \frac{1}{2}m \times 2gR$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ = mgR$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.