A sonar generator on a ship produces periodic ultrasonic waves at a frequency of 2.2 MHz. The wavelength of the waves in seawater is 5.310-4 m. When the generator is directed downward, an echo is received 15.2 s later. How deep is the ocean in m?

Answer 1

frequency(1/s)*wavelength(m) = speed(m/s)
speed(m/s)*time(s) = distance

so

(2.2*10^6/s)(5.3*10^-4 m)(15.2s) = 17723m

so, the depth is half the distance traveled, or 8862m