Question

A circular ring of mass 6kg and radius a is placed such that its centre lies at the origin. The two particles of masses 2kg each are placed at the intersecting points of the circle with positive x axis and positive y axis. Then the angle made by the position vector of centre of mass of entire system with x axis is

Answer 1

.X CM = ma/2m = a/2 ; Y CM = ma/2m = a/2 ; tan theta = X CM/Y CM = (a/2)/(a/2)=1 So, theta = 45 degree..