A police car siren emits a frequency of 2010 Hz when stationary. When it is driving toward a stationary car, the other driver hears a frequency of 2120 Hz. How fast is the police car driving? (Speed of sound = 343 m/s) Police car speed:
a) 20 m/s
b) 25 m/s
c) 30 m/s
d) 35 m/s
