As the ambulance approaches, the pedestrian will hear a higher frequency. As it recedes a lower frequency. Add the absolute values of the changes.
For the formula, Google Doppler shift (classical not relativistic)
Not at all sure where to start with this problem. Any help would be appreciated!
The siren of an ambulance has a frequency f=500 Hz. A pedestrian standing on a
sidewalk listens to this siren as the ambulance passes by at a speed of 65 mph. The speed
of sound in air is 330 m/s.
Calculate the total shift in frequency detected by the pedestrian as the ambulance
passes.
2 answers
http://formulas.tutorvista.com/physics/doppler-shift-formula.html
1 answer