Question

an athelete completes one round of circular track of radius in 40 sec what will be his displacement at the end of 2 minute 20sec

Answer 1

In first 2 minutes it returns to its initial position as it completes 3 revolutions. in last 20 seconds it completes half of the circle . hence displacement is 2 times the radius of the circle as it is shortest possible path .

Answer 2

diameter
since displacement is zero until 2 minute as 120+20
the remaining 20 sec she will cover half the track and hence the dia