Question

A boy is running along a circular track of radius $7m$. He completes one circle in $10seconds$. The average velocity of the boy is

• A. $4.4m{s}^{-1}$
• B. $0.7m{s}^{-1}$
• C. Zero
• D. $70m{s}^{-1}$

Answer 1

The correct option is C

Zero

(C): Zero

Step 1: Given data

Radius r=$7m$

Time taken by the athlete to complete one round of circular track $∆t$=$10seconds$

Step 2: Definition

1. Average velocity is measured as the change in displacement divided by the total time interval.
2. If the initial and final point is the same as a moving body then the change in displacement of the object is zero.

Step 3: Calculating the average velocity

$v=\frac{∆x}{∆t}$

Here v is the average velocity, $∆x$ is the change in displacement, $∆t$ is the time interval.

The initial and final point is the same so, $∆x=0,$ $∆t=10sec$

So, v = Zero.

Thus, the average velocity of the boy is Zero.

Hence, Option (C) is the correct answer.