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. zeroC. `(mv^(2))/(r^(2))`D. `(pi r^(2))/(mv^(2))`

A body of mass m is moving in a circle of radius r with a constant spe

1.	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. zeroC. `(mv^(2))/(r^(2))`D. `(pi r^(2))/(mv^(2))`
Answer» Correct Answer - B Work done by centripetal force is alwase zero because force and instantaneous displacement are always perpendicular `W = vecF - vec S = F s cos theta s cos (90^(@)) = 0`

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