A police car is moving towards the east at 34.0 m/s while sounding its siren. There is a wind blowing from the west with a speed of 15.0 m/s. A second police car is ahead of the first police car and is sounding its identical siren while moving towards the east at 32.0 m/s. A policeman in the first police car hears a beat frequency of 4.80 Hz between the two sirens. The speed of sound in air is 343. m/s.
Calculate
(a) the frequency of the siren;
(b) the beat frequency heard by the policeman in the second police car;
(c) the frequency from the siren of the faster police car heard by a person standing on the sidewalk between the two cars.

Answers
(a) 864.0 Hz
(b) 5.333 Hz
(c) 954.7 Hz


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Relevant equations

f1=f(V-Vd/V-Vs)


i think v=343-15
          v=328m/s

Besides the above, I'm Clueless. Can someone help me out?

Thanks guys

Last edited by bio_mechanical_hazard (2008-04-13 19:39:11)