A particle of mass m is suspended from a ceiling through a string of length L. The particle moves in a horizontal circle of radius r. Find the speed of the particle.

Question

$\begin{array}{1 1} v=rg\;\tan\;\theta \\ v= \sqrt{(rg\;\tan \theta)} \\v=mg \;\cos \theta\\ v=\sqrt{(mg \cos \theta )}\end{array}$