Question

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

Answer 1

Answer:

Explanation:

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 = 0.5 × 2 × 22 × 100

⇒ Distance covered = 2200 m

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

And the displacement is 200 m as it will be equal to the diameter.

Answer 2

Explanation : diameter = 200m.

Radius = 100m , Time taken to complete one round (t) = 40s total time = 2 minute 20 second = 1 minute = 60 second , 2*60+20 = 140s , = 140 / 40 = 3.5s , distance covered in one round= circumference in circular track = 2πr 3.5 round = 3.5 *2*22/7*7 = 2200m , displacement= 200m