A stationary destroyer is equipped with sonar that sends out pulses of sound at 49.0 MHz. Reflected pulses are received from a submarine directly below with a time delay of 60.0 ms at a frequency of 48.966 MHz. If the speed of sound in seawater is 1.58 km/s, what is the depth of the submarine? What is the magnitude of the submarine's vertical speed?
r or Vs = 1.58 km/s
t = .06s
d = rt
fL = fS(Vs + VL)/(Vs + VSource)
The Attempt at a Solution
I found the first part simply by using d = rt. And because that is the distance of the sonar wave to the submarine and back to the destroyer I divided the answer by 2 and got the answer of 47.4 meters.
For the second part, I am fairly certain this is doppler problem and when I solved for VL I got the answer of 1.096 m/s which was wrong. Any hints for how to go about solving for the vertical velocity of the submarine?