Sound and Music - Mission SM4 Detailed Help


A source of sound produces sound waves with a frequency of f. As the source of sound approaches an observer, the _____.


 
The Doppler Shift:
If a source of waves is moving towards an observer, then the frequency at which the waves arrive at the observer is greater than the frequency at which the waves are produced by the source. If a source of waves is moving away from an observer, then the frequency at which the waves arrive at the observer is less than the frequency at which the waves are produced by the source. There is an upward shift of the observed frequency when the source approaches and a downward shift in frequency when the source recedes (moves away).

 
Whether the observed frequency is greater than or less than the frequency at which waves are produced depends upon whether the source is approaching or receding (moving away) from the observer. See Know the Law section.