A stationary detector measures the frequency of a sound source that first moves at constant velocity directly toward the detector and then (after passing the detector) directly away from it. The emitted frequency is f. During the approach the detected frequency is f'app and during the recession it is f'rec. If ( f'app - f'rec)/f = 0.695, what is the ratio vs /v of the speed of the source to the speed of sound?

Question

anonymous · Answer

Remember formula for Doppler effect?

anonymous · Answer

yes Doppler formula is very useful here