Sound V2. An observer and a sound source move along the same straight line, both at constant speeds. The observer moves at a speed of 60 m/s and the sound source at a speed of 40 m/s. The sound source emits a signal with the frequency 1200 Hz (Vsound = 340 m/s). a) What frequencies does the observer perceive if the observer and the sound source travel in the same direction? Calculate this before and after the observer passes the sound source. b) What frequencies does the observer perceive as the observer and the sound source travel in opposite directions? Calculate this before and after the observer passes the sound source