Question

Problems for Practice
1. A boy is moving in a circle of diameter 5 m. Calculate the distance covered and the displacement when he
completes 4 revolutions.
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Answer 1

Answer:

diameter of the circle = 5 m radius of the circle = 2.5 m circumference of the circle = 2nr = 2 x 22/7 x 2.5 = 15.71 cm distance covered by the particle = 3 x 15.714 = 47.14 cm

Answer 2

Answer:

Distance covered = 4 revolutions = 62.8 m

Displacement = zero because start point and end point is same

Explanation:

1 revolutions = 1 circumference

1 revolutions = $\pi D$

1 revolutions  = $\pi * 5$

4 revolutions  = 4 * 3.14 * 5

4 revolutions  = 3.14 * 20

4 revolutions  = 62.8 m

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Distance covered = 4 revolutions = 62.8 m

Displacement = zero because start point and end point is same