Question

An athlete completes one round of a circular track of diameter 200 m in 40 s. What will be the distance covered and the displancement at the end of 2 minutes 20 s

Answer 1

10m displacement answer

Answer 2

Diameter of circular track = 200 m

radius = diameter/2 = 100cm

time taken by athlete for 1 round = 40 s

so , distance covered in 1 round = circumference of track = 2π r

hence , speed of the athlete = distance / time

= 2πr/t  = 2*22/7 *100 / 40 = 4400 / 7 * 40

distance covered in 2 min 20 sec = speed * time

= 4400 7 * 40* 140 sec                      ( as 2min 20sec = 140 sec)

=2200 m

if athlete takes 40s for a round then 140 secs for 140 /3, that is 3 and 1/2 rounds.

hence displacement = diameter of the track = 200m