Question

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. $\frac{m{v}^2}{r^2}\times \pi r$
• D. $\frac{\pi r^2}{m{v}^2}$

Answer 1

The correct option is A Zero

Work done by centripetal force is always zero. As the force is acting towards the centre so, the work done by this force in moving the body over half the circumference of the circle is zero.