Question

Give one example of a situation in which a body has a certain average speed but its average velocity is zero.

Answer 1

1. Consider a situation in body is moving in circular path. Suppose, a body starts its motion from point A. Body come back to its original place after completing 1 complete rotation.So, total displacement =0
2. As body is back to its original position but total distance = length of circular track, $speed=\frac{distance}{time}$ as distance is not zero so speed will also not zero.
3. Whereas. $velocity=\frac{displacement}{time}$
4. $v=\frac{0}{t}=0$

Hence velocity is zero while speed is not zero