Question

1.It is not possible to have a situation in which speed of particle is never zero but the average speed in an interval is zero.

2. It is not possible to have a situation in which the speed of particle is always zero but the average speed is not zero.

Explain the above statements.

Answer 1

Case: 1: .It is not possible to have a situation in which speed of particle is never zero but the average speed in an interval is zero.

1. As particle is in motion it means, some distance is covered by the particle.
2. So, From $speed=\frac{Distance}{time}$ will never be zero since some distance is covered by the particle.
3. And for $Averagespeed=\frac{totaldistance}{totaltime}$ ,since particle is in motion so distance can not be zero, so average speed in an interval will not be zero.

Case:2: It is not possible to have a situation in which the speed of particle is always zero but the average speed is not zero.

1. As particle is in rest it means, distance=0, is covered by the particle.
2. So, From $speed=\frac{Distance}{time}$ will be zero, since distance=0 is covered by the particle.
3. And for $Averagespeed=\frac{totaldistance}{totaltime}$ is also zero,since particle is in rest so distance will be zero, so average speed in an interval will alsoA be zero.