Answer:
The beat frequency is 0.0019 MHz.
Explanation:
Given that,
Velocity = 0.32 m/s
Frequency = 4.40 MHz
Speed of wave = 1540 m/s
We need to calculate the frequency
Case (I),
Observer is moving away from the source
Using Doppler's effect
Where, v' = speed of observer
Put the value into the formula
Case (II),
Cell is as the source of sound of frequency f' and it moving away from the observer.
Using formula of frequency
We need to calculate the beat frequency
Hence, The beat frequency is 0.0019 MHz.