Question

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

Answer 1

Given parameters

The diameter of the circular track = 200 m

Radius (r) = 200/2

r = 100 m

Time is taken by an athlete to complete one round = 40 seconds.

Displacement = ??

Speed = Distance/Time

Total time athlete moves – 2 min 20 seconds

2 min 20 seconds = 2 × 60 + 20

2 min 20 seconds = 140 seconds

Need to find the distance covered in one round

Distance covered in one round = Circumference of circle

Distance covered in one round = 2πr

Distance covered in one round = 2

Distance covered in one round = 2 × 100π

Distance covered in one round =200π

Time is taken by an athlete to complete one round = 40 seconds.

Number of rounds completed in 140s = 140/40

Number of rounds completed in 140s = 35

Distance covered = 3.5 × circumference

Distance covered = 3.5 × 2πr

Distance covered = 3.5 × 2 × 3.14 × 100

Distance covered = 2200 m

Hence, the distance covered at the end of 2 min 20 seconds is 2200 m or 22 km.

Hope it's help u mate

Answer 2

Answer:

Given :-

• Diameter of circular track = 200 m
• Radius, r = 200/2 = 100 m
• Time taken by athlete to complete one round = 40 seconds.

To Find :-

• Distance covered = ??
• Displacement = ??

Formula to be used :-

• Speed = Distance/Time
• Circumference of circle = 2πr

Solution :-

2 min 20 seconds = 140 seconds

Number of rounds = 140/40 = 3.5

⇒ Distance covered = 3.5 × circumference

⇒ Distance covered = 3.5 × 2 × 22/7 × 100

⇒ Distance covered = 5 × 2 × 22 × 100

⇒ Distance covered = 2200 m

Hence, the distance covered at the end of 2 min 20 seconds is 2200 m.

And displacement is 200 m as it return to initial position again.

Explanation:

Hope it helps! :)