Doppler Effect of Sound How do you calculate the frequency of the listener if both the source and listener are moving at certain speeds towards each other?
My problem here is that from my sources we have only been taught how to calculate frequencies when either the source or the listener is stationery so now I dont know how to manipulate the Doppler equation to suit the scenario at hand.
 A: The equation is:

Where:
       vs = Velocity of the Source
       vo = Velocity of the Observer
       v = Velocity of sound or light in medium
       f = Real frequency -- the frequency the source is omitting
       f' = Apparent frequency -- the frequency the observer sees/hears

This equation is for the source and the observer travelling towards each other.   Multiply the stuff inside the two parentheses to change the direction of either the source or the observer (multiply the top parenthesis by -1 to change the direction of the observer, the bottom by -1 to change the direction of the source).   
For instance, for the observer moving towards the source but the source moving away from the observer the formula would be:  


The velocity of sound in air is about 343 meters per second.
The velocity of light in air is almost the same as the speed of light (c) -- its a bit slower at about 299700000 m/s
Look up the specific speed for your desired wave (light or sound) for your desired medium (the stuff the wave is passing through)
