Why would you not like to use a measuring tape made of an elastic material like rubber to measure distance? What would be some of the problems you would meet in telling someone about a distance you measured with such a tape?

Explanation

Particle moving in semicircular path from 'A' to 'B' in 2 seconds.
Distance = 22 m
Displacement = 14 m
Speed = `("Distance")/("Time")=(22)/(2) = 11 m s^(-1)`
Velocity = `("Displacement")/("Time") = (14m)/(2) = 7 m s^(-1)`
1 kilometre per hour = 1 kmph = `(5)/(18)m s^(-1)`
1 mile per hour = 1 mph = 0.447 m `s^(-1)`