Assuming that the average speed of sound waves in water is 1500 meters per second, determine the water depth if the signal sent out by an echo sounder requires 6 seconds to strike bottom and return to
the recorder.

4500 m

Explanation:

Within 6 seconds the signal will cover = 1500m/second x 6 seconds = 9000 meters

As it is an echo sounder, it has covered twice the distance; one phase of going and one phase of coming

We need to calculate one phase of the distance that will give the actual depth:

So the distance will be 9000/2 = 4500 meters

Therefroe, the water depth will be 4500 meters