Here's how it works:
* Source at Rest: When the source of sound (the moving object) is at rest, the frequency of the sound waves emitted is the same for all observers.
* Source Moving Towards Observer: If the source is moving towards an observer, the sound waves are compressed, resulting in a higher frequency (higher pitch).
* Source Moving Away From Observer: If the source is moving away from an observer, the sound waves are stretched out, resulting in a lower frequency (lower pitch).
The formula for the Doppler effect is:
f' = f (v ± v_o) / (v ± v_s)
where:
* f' is the observed frequency
* f is the source frequency
* v is the speed of sound in the medium
* v_o is the speed of the observer (positive if moving towards the source, negative if moving away)
* v_s is the speed of the source (positive if moving towards the observer, negative if moving away)
In summary:
* The frequency of a sound wave from a moving object is not constant.
* The observed frequency is higher than the actual frequency if the source is moving towards the observer.
* The observed frequency is lower than the actual frequency if the source is moving away from the observer.
The Doppler effect is a common phenomenon experienced in everyday life, such as the changing pitch of a car horn as it passes by or the apparent change in frequency of an ambulance siren as it approaches and then moves away from you.
