Answer:
a) The frequency the driver observes as the police car comes = 3036.3 Hz
b) The frequency the driver detects as the police car passes him = 2075.7 Hz
Step-by-step explanation:
The Frequency of the sound, fs = 2500 Hz
The speed of sound in air, v = 343 m/s
The speed of the driver Northbound, vo = 25 m/s
The speed of the driver Southbound, vs = 40 m/s
a) The frequency the driver observes as the police car comes is calculated below

b) The frequency the driver detects after the police car passes him is calculated below
