# A sonar echo returns to a submarine 1.20 s after being emitted. what is the distance to the object creating the echo? (assume that the submarine is in the ocean, not in fresh water.)

Oct 5, 2015

I found: $918.6 m$

#### Explanation:

Considering (from the literature) a speed of sound of $1531 \frac{m}{s}$ we have:

$\text{speed"="distance"/"time}$ where distance is twice $d$ (going to and coming back from the object), so:
$1531 = \frac{2 d}{1.2}$

$d = \frac{1.2 \cdot 1531}{2} = 918.6 m$