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Question
Exercise Problems.
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?
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Solution
Given: Diameter of circular track = 200m
time to complete = 40s
Formula: Circumference of circular track = d. π m
speed = `"distance"/"time"`
Solution:
Circumference of the track = d.π
= 200 × 3.14 = 628m
speed = `"628m"/"40s"` = 15.7 ms– 1
Distance covered in 2 min 20 s = speed × time
In the given time athlete covers 31/2 rounds = 2198m
The final position of athlete is as shown in figure (A – initial position, B – final position)
∴ Displacement = Distance × time
= 200 m
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