You are at a stop light in your car, stuck behind a red light. Just before the light is supposed to change, a fire engine comes zooming up towards you traveling at a horrendous 85.0 km/h. If the siren has a rated frequency 665 Hz, what frequency of the sound do you hear

The frequency of the sound you will hear is 713.85 Hz

Explanation:

Given;

speed of your car, = 85.0 km/h

frequency of the siren, f = 665 Hz

Speed of sound in air, v = 345 m/s

The frequency of the sound you hear, can be calculated as;

Convert the speed of the car to m/s

Therefore, the frequency of the sound you will hear is 713.85 Hz