Question

A stone of mass m is moved in a circle of radius r with constant speed v.The work done by the force over half of circumference of the circle is

Answer 1

then the force is mv^2/r and distance is πr then w=f*d = mv^2/r*πr you get 2mvr

Answer 2

Answer:

zero work

Explanation:

moving body (stone ) is perpendicular to the centre of the circle

therefore , W = F × s × cosθ

                      = F × s × cos 90

                      = 0  ( cos 90 = 0)