Question

a body moving in a circular path with constant speed. how much work is done in one complete rotation of this motion

Answer 1

Since the mass is revolving in the circular path at a constant speed, it means it is in a uniform circular motion. The Centripetal force acting on the mass at any instant is perpendicular to the displacement of the mass. Thus, no work is done on the mass whatever be the displacement.
Here displacement is zero because starting and ending point is same.So,workdone is zero.