Question

A bat in search of prey hears the echo of its squeak after $0.1\text{s}$. How far is the prey from the bat, if the squeak got reflected from it?

$($speed of sound in air $=340\text{m/s})$

• A. $34\text{m}$
• B. $17\text{m}$
• C. $40\text{m}$
• D. $54\text{m}$

Answer 1

The correct option is B $17\text{m}$

Let the distance of the prey from the bat be $d$.

In $0.1\text{s}$, sound will travel a distance of $2d$.

So, $v=\frac{s}{t}\Rightarrow 340=\frac{2d}{0.1}$

$\therefore d=17\text{m}$