Question

A body of mass $100g$ is rotating in a circular path of radius $r$ with constant velocity. The work done in one complete revolution is:

• A. $\frac{r}{100}J$
• B. $\frac{100}{r}J$
• C. $100r$
• D. zero

Answer 1

The correct option is D zero

We know that total work done is equals to change in kinetic energy plus change in potential energy.

Kinetic energy-

In this case there is no change in the velocity so change in kinetic energy is zero.

Potential energy-

There is no change in the height of the object hence change in potential energy is also zero.

So there is no work donw on the body.