Question

a body is moving along a horizontal circular path.how much work is done by the weight?

Answer 1

no work is done .. because:
1. displacement is 0
2. displacement is normal to direction of fore i.e., tetha = 90°...

Answer 2

In uniform circular motion, resultant force which is known as centripetal force is directed towards centre while object moves at right angles to it at any instant hence there is no component of force in the direction of motion. Only one component remains
Which does not do work at all ( W = F x S )
Hence the work done in a uniform circula motion is always zero