Q3 of 58 Page 37

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

Given: diameter of circular track(d) = 200 m

Time is taken to complete one round = the 40s


Therefore, length of the track = π d


= 200π


Speed of the athlete= distance travelled/time taken


= 200π /40


= 5π m/s


Distance covered after 2m 20s (140s)


Distance = speed × time


= 5π× 140


=700π (m)


During the coverage of 700π (m) the athlete makes 3 and half round of the circular track. So the displacement is equal to the diameter of the track = 200 m.


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