Question

an athlete completes one round of a circular track of radius R in 40 seconds what will be his displacement at the end of 2 minute 20 seconds

Answer 1

in 2 min 20 sec there is 2×60+20= 140
sec. therefore 3 full and 1 half round of circular track will be covered hence displacement will be displacement of diameter = 2R
answer is 2R

Answer 2

ANSWER:
Displacement :The minimum possible distance of an object from its starting point to its end point.

Total Time=2minutes+20seconds
=120+20.=140seconds.
Time taken to complete one full round =40.
So,140/40=3.5rounds have been completed .3rounds and a half round is completed so,yome taken to complete the half round will be 40/2=20s and the athlete is 2πr/2=πr distance away from the starting point. So, the displacement is 2r.