question_answer

A body of mass \[m\] is moving in a circle of radius \[r\] with a constant speed \[v\]. The force on the body is \[\frac{m{{v}^{2}}}{r}\] and is directed towards the centre. What is the work done by this force in moving the body over half the circumference of the circle                                  [NCERT 1977; RPET 1999]

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

B)                      Zero

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

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