A police car travels due east along a straight road at 25 m/s while sounding a 680 Hz…
PHYSICS · Single correct · A Level · Physics · Waves · Waves
Problem
A police car travels due east along a straight road at 25 m/s while sounding a 680 Hz siren. A pedestrian stands 50 m due north of the point of closest approach to the car. Which of the following best approximates the frequency the pedestrian hears at the instant the car is at that point of closest approach? (Assume the speed of sound in air is 340 m/s.)
(a) 734Hz
(b) 717Hz
(c) 680Hz
(d) 634Hz