Question

An athlete completes one round of a circular track of diameter 200m in 40 sec . What will be the distance covered

Answer 1

Distance travelled = circumference of the circular track
= 2×pi×radius
=2×3.14×100 = 628 m.

dear student i think you question is incomplete. If you want to find out the distance travelled at aparticula time folloe these steps:
speed = distance / time
= 628/40 = 15.7 m/s.

distance = speed×time.

if you want to find the distance at a particular time, multiply the time with speed (15.7)