question_answer

A body of mass m is moving in a circle of radius r with a constant speed v. If a force \[\frac{m{{v}^{2}}}{r}\] is acting on the body towards the centre, then what will be the work done by this force in moving the body over half the circumference of the circle?

A)  zero                     

B)  \[\frac{m{{v}^{2}}}{{{r}^{2}}}\]

C)         \[\frac{m{{v}^{2}}}{r}\times \pi r\]         

D)         \[\frac{\pi {{r}^{2}}}{m{{v}^{2}}}\]