# Math Help - Cirucular motion

1. ## Cirucular motion

A particle P of mass m is at rest at a point A on the smooth outer surface of a fixed sphere of center O and radius a, OA being horizontal.the particle is attached to one end of a light inextensible taut string,which passes over the sphere and carries at it's other end a particle Q of mass 2m which hangs freely in the vertical plane containing OA.the system is released from rest and after a time t the angle POA is $\theta$,as shown in the picture.show that while p remains in contact with sphere.

$3a\left(\frac{d\theta}{dt}\right)^2=2g(2\theta-\sin\theta)$