Question

1. 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 minutes 20 s?​

Answer 1

Explanation:

in 40s 200 m

ok

2 min 20 sec

is equal to 160 sec

then 40×4= 200×4

800 m distance

displacement= 0 ,if circular field length is 200m

Answer 2

GivEn:

• Diameter of circular track = 200 m

• Radius of circular track = $\sf \cancel{ \dfrac{200}{2}}$ = 100 m

• Time taken by Athlete to complete one round = 40 s

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To find:

• Distance covered and displacement at the end of 2 min 20 s.

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SoluTion:

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★ 2 min 20 s = 140 seconds

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In 40 sec athlete complete one round

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So, In 140 sec he will complete = $\sf \cancel{ \dfrac{140}{4}} = 3.5\;rounds\;\;\;\;\:\:\:\bigg\lgroup\bf 2\;min\;20\;s = 140\;sec\bigg\rgroup$

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One round = Circumference of Circle

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Therefore,

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Distance covered in 140 sec = $\sf 2 \pi r \times 3.5$

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$:\implies\sf 2 \times 3.14 \times 100 \times 3.5$

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$:\implies\sf 2 \times \dfrac{314}{ \cancel{100}} \times \cancel{100} \times 3.5$

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$:\implies\sf 2 \times 314 \times 3.5$

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$:\implies{\underline{\boxed{\bf{\pink{2200\;m}}}}}\;\bigstar$

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$\therefore$ Hence, the distance covered at the end of 2 min 20 s is 2200 m.

And Displacement is 200 m (diameter) as it return to initial position again.