Question

an athlete completes one round of a circular track of diameter 200m in the 40sec what will be the distance covered and the displacement the end of in 2 minute 20 second

Answer 1

radius= 100 m
Perimeter=2πr=628.57 m
speed=distance/time = 628.57/40 = 15.7 m/s
Distance covered after 2 mins 20 sec= speed*time=15.7*140=2200 metres
to find the displacement we have to find how many rounds has he completed which we get by taking the no. of rounds he has completed
no of rounds=distance covered/perimeter=2200/628.57 = 3.5
this means that he is half-way in the 4th round which means the displacement is the diameter
thus displacement=200 meters

hope this helps!