An athlete completes one round of a circular track of diameter 200m in 40 seconds What will be the difference covered and the displacement at the end of 2 minutes 20 seconds?

Answer 1

Athlete covers 2pi radians in 40 s. So angular velocity = pi / 20 rad/s

Hence the velocity = r w

r = 100 m. So v = 5 pi m/s

Hence the distance covered in 2 min 20 s ie 140 s = 700 pi metre.

Displacement is the shortest distance between initial and final position

In 140 s, 3 full rotation and one half rotation. So the he will be diametrically opposite. Hence the displacement is equal to 200 m ie diameter of the circular track.