Doppler Effect....Ahhhh! 1. The problem statement, all variables and given/known data A student in a parked car honks the horn, which has a `proper' frequency of 310.00 Hz. An observer in an approaching vehicle measures the frequency of the sound to be 342 Hz. Calculate the speed of the approaching vehicle. Use 340 m/s as the speed of sound in air. 2. Relevant equations Fo / V + Vo = Fs / V + Vs Fs = 310 Hz Vs = 0 m/s Fo = 342 Hz Vo = ? V = 340 m/s 3. The attempt at a solution Vo = (Fs / V + Vs) * (V / Fo) I know this is where I am messing up because I am not getting the right answer. Can someone show me where I am going wrong.