Question

A ship sends on a high frequency sound wave and receives an echo after 1 second. What is the depth of the sea? Speed of sound in water is 1500 m/s :

• A. $375m$
• B. $750m$
• C. $1500m$
• D. $2250m$

Answer 1

The correct option is B $750m$

Velocity of sound in water $v=1500m/s$

Let the depth of sea be $x$.

The sound has to travel to the bottom of the sea and get reflected back to the ship itself, thus total distance traveled by the sound is $2x$.

Time taken to hear an echo $t=1$ s

So, $2x=vt$

Or $2x=1500\times 1$

$⟹x=750m$