Question

A 2450-Hz sound source and an observer are moving away from each other. The source is moving at 15.0m/s, and the observer is moving at 25.0m/s. Assuming the speed of sound to be 343 m/s, what is the frequency heard by the observer?

Answer 1

`f'=2176.256983Hz`

Step-by-step explanation:

The relationship between observed frequency f' and the emitted frequency f is given by the doppler effect equation. In this case the observer and the source are moving in opposite direction away from each other, so:

`f'=(c-v_0)/(c+v_s) f`

Where:

`c=Speed-of-the-sound-waves=343m/s`

`v_0=Velocity -of-observer=25m/s`

`v_s=Velocity -of-source=15m/s`

`f=Emitted -frequency=2450Hz`

`f'=Observed-frequency`

Evaluating the data in the equation:

`f'=(343-25)/(343+15)*2450=2176.256983Hz`