question_answer

Explain that a body can have zero average velocity but not zero average speed. Show that average velocity of the object over an interval of time is either smaller than or equal to the average speed of the object over the same interval.

Answer:

                Average velocity = displacement/(total time taken) and average speed = total distance travelled/(total time taken). If an object completes a circular path of radius r in time r, then its displacement is zero but distance travelled by body is \[2\pi r\]. Therefore, the average velocity of body = zero but average speed of body =\[2\pi r/t\].