Question

A bat echolocates its prey at $32\text{m}$. If the speed of its ultrasound is $328\text{m/s}$, compute the time required for it to have located its prey.

• A. $0.46\text{s}$
• B. $0.19\text{s}$
• C. $0.26\text{s}$
• D. $0.39\text{s}$

Answer 1

The correct option is B $0.19\text{s}$

Given:
Distance of prey from the bat, $d=32\text{m}$
Speed of ultrasound, $v=328\text{m/s}$
Since the sound wave sent by the bat will travel a distance of $2d$ with the velocity $328\text{m/s}$,
So, time taken by bat to locate the prey is the time taken by ultrasound wave to travel to prey and reflect back to the bat,
$t=\frac{2d}{v}=\frac{2\times 32}{328}$
$⟹t=0.19\text{s}$