Q. A particle of mass $m$is being circulated on a vertical circle of radius $r.\ $If the speed of particle at the highest point be$\ v,$ then
A) $mg = \frac{mv^{2}}{r}$
B) $mg > \frac{mv^{2}}{r}$
C) $mg < \frac{mv^{2}}{r}$
D) $mg \geq \frac{mv^{2}}{r}$
Explanation
(c) Net force towards centre=centripetal force
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$T - mg\ cos\theta = \frac{{mv}^{2}}{r}$
At point C, $\theta = 180{^\circ}$
$T + mg = \frac{mv^{2}}{r}$
$\ \Longrightarrow \ \ \ \ \ \ \ \ \ \ \ \ mg < \frac{mv^{2}}{r}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.