Q. A body of mass $m\ kg$ is rotating in a vertical circle at the end of a string of length $r$ metre. The difference in the kinetic energy at the top and bottom of the circle is
A) $\frac{mg}{r}$
B) $\frac{2mg}{r}$
C) $2mgr$
D) $mgr$
Explanation
(c) Difference in K.E. = Difference in P.E. $= 2mgr$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.