5. Standing on a sidewalk, you see a car and an ambulance moving along the road, as shown in the figure below. The speed of the car is 25 m/s. You hear a fre- quency of 550 Hz from the siren of the ambulance as it approaches you, and a frequency of 440 Hz as it passes you. Vair = 343 m/s] (a) What is the speed of the ambulance? (b) What is the frequency of sound emitted by the ambulance? (c) What frequency is heard by the driver of the car when it is in front of the ambulance? (d) What frequency is heard by the driver of the car when it is behind the am- bulance? ambulance W car you