Consider a collection of large number of particles, each moving with speed 'v'. The direction of velocity is randomly distributed in the collection. Show that the magnitude of the relative velocity between a pair of particles averaged over all the pairs in the collection is greater than 'v'.
Thank You!
See if the attachment below gives some idea.... the step where average is found, the formula for the average of a function is used from definite integral for which if you need you can refer to a calculus text.
123iitjee_forum_relative_velocity.gif