Question

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

Answer 1

length AB=200m=2R

time taken to complete one round=40 sec

let the starting point be A

in 140 sec or 2 min 20 sec number of rounds completed=14040=3.5

distance traveled=3.5 * (2*π*R)=3.5*2*π*100 m=2200 m (approx)

displacement refers to change in position from the starting point.the final point is B

as after 3.5 revolutions(starting from A) the athlete will be at B.

displacement=200m