Question

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

Answer 1

An athlete completes one round of a circular track of diameter 200m in 40s.

Given that, the diameter is 200 m. So, the radius is 100 m (half of diameter).

Distance covered in one round (during 40 seconds) = 2πr

(2πr = Circumference of the circle)

→ 2 × 22/7 × 100

→ 4400/7

→ 628.571 m

Distance covered in 1 second (during first or one round) = 628.571/40 = 15.714 m

We have to find the distance covered and the displacement at the end of 2min 20s.

Displacement is zero (as the path is circular). But the athele covers 3.5 rounds (140/40). So, the displacement of the athele is equal to it's diameter of circle i.e. 200 m.

Distance covered in 2 min 20 sec or 140 sec = 15.714 × 140 = 2199.96 = 2200 m (approx.)