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 of 2min 20s?

Answer 1

2198 meters

Explanation:

First we need to find out the velocity of the athlete from the formula. Such as

Velocity = distance / time

But the distance of one round of circular track is equal to the circumference of he circles. We are given the diameter. Thus, to calculate circumference

Distance = circumference = 2 * pi* d/2 = pi * d = 3.14 * 200 = 628 m

Substituting the values in formulas. We get,

velocity = 628/40 = 15.7 m/s

Now, we can calculate the displacement or the distance covered in 2 min and 20 sec

2 min and 20 sec = 140 sec

Substituting values in formulas

displacement = velocity * time

displacement = 15.7 m/s * 140 s = 2198 meters

Answer 2

Distance covered = 628.57 m

Displacement = 2.2 Km

Explanation:

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

Find: The distance covered and the displacement at the end of 2min 20s

Solution:

Distance covered = circumference of the track = 2πr = 2 * 22/7  * 200/2 = 628.57 m

So velocity will be distance / time = 628.57 / 40 = 15.71 m/s

t = 2min 20s = 140s

Displacement = velocity * time = 15.71 * 140 = 2199.4 m = 2.2 Km