Q. A simple pendulum of length L and mass of bob M is oscillating in a plane about a vertical line between angular limits$\ - \phi\ and + \phi$. For an angular displacement$|\theta| < \phi$. the tension in the string and the velocity of the bob are T and $v$ respectively. Which of the following relation holds good under the above conditions?
A) $T\cos{\theta = Mg}$
B) $T{- \ Mg\ cos}{\theta = Mv^{2}/L}$
C) $T{+ \ Mg\ cos}{\theta = Mv^{2}/L}$
D) $T = Mg\cos\theta$
Explanation
(b) $Mg\cos\theta$ will provide the required centripetal force,
So, $T - Mg\cos\theta = mv^{2}/L$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.