Answer:
12.64968 Hz
Step-by-step explanation:
v = Velocity of sound in seawater = 1522 m/s
u = Velocity of dolphin = 7.2 m/s
f' = Actual frequency = 2674 Hz
From Doppler effect we get the relation

The frequency that will be received is 2661.35032 Hz
The difference in the frequency will be
