A body of mass m is moving in a circle of radius r with a constant speed v, The force on the body is `(mv^(2))/(r )` and is directed towards the centre what is the work done by the from in moving the body over half the circumference of the circle?
A. `(mv^(2))/(pir^(2))`
B. zero
C. `(mv^(2))/(r^(2))`
D. `(pir^(2))/(mv^(2))`

A body of mass m is moving in a circle of radius r with a constant speed v, The force on the body is `(mv^(2))/(r )` and is directed towards the centre what is the work done by the from in moving the body over half the circumference of the circle?
A. `(mv^(2))/(pi r^(2))`
B. zero
C. `(mv^(2))/(r^(2))`
D. `(pi r^(2))/(mv^(2))`