Pls solve all this question class 9 science ch motion

Dear student

Diameter of a circular track, d = 200 m

Radius of the track, r =

Circumference = 2πr = 2π (100) = 200π m

In 40 s, the given athlete covers a distance of 200π m.

In 1 s, the given athlete covers a distance =

The athlete runs for 2 minutes 20 s = 140 s

∴Total distance covered in

The athlete covers one round of the circular track in 40 s. Thismeans that after every 40 s, the athlete comes back to his originalposition. Hence, in 140 s he had completed 3 rounds of the circulartrack and is taking the fourth round.

He takes 3 rounds in 40 × 3 = 120 s. Thus, after 120 s hisdisplacement is zero.

Then, the net displacement of the athlete is in 20 s only. In thisinterval of time, he moves at the opposite end of the initialposition. Since displacement is equal to the shortest distancebetween the initial and final position of the athlete, displacementof the athlete will be equal to the diameter of the circular track.

∴ Displacement of the athlete = 200 m

Distance covered by the athlete in 2 min 20 s is 2200 m and hisdisplacement is
200 m.

Regards
 

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