How deep was the ocean at the point?

Question

Sound travels at 1530 m/s in sea water. A signal sent down from a ship is reflected at the bottom of the ocean and returns 3.5 s later. Assuming the speed of sound was not affected by changes in the water, how deep was the ocean at the point?

a	2677.5 m
b	1287.6 m
c	437.1 m
d	956.8 m

Answer 1

We are given the velocity of sound in the ocean (v=1530 m/s) and the time which it takes for the sound wave to travel from the surface to the bottom and back (t=3.5 s). We know that the velocity times the time traveled gives the total distance traveled. In this case, the total distance is two times the depth of the ocean (h) at the measurement point. So 2h = v*t. Now, we can plug in the numbers and solve for h.