A heavy sphere of mass $M$ and radius $R$ is suspended from a point $P$ against a smooth vertical wa

Question

A heavy sphere of mass $M$ and radius $R$ is suspended from a point $P$ against a smooth vertical wall with a string of length equal to the radius of the sphere. The magnitude of normal reaction between the sphere and the wall is

Professor PC Thomas Classes · Answer

Note that string makes an angle $30^{\circ}$ with the vertical. Therefore, $ T \cos 30^{\circ}=M g $ and $\quad T \sin 30^{\circ}=N$ or $\quad N=M g 	an 30^{\circ}=\frac{M g}{\sqrt{3}}$