Question

A stationary police car emits a sound of frequency 1205 Hz that bounces off of a car on the highway and returns with a frequency of 1255Hz. The police car is right next to the highway, so the moving car is traveling directly toward or away from it.

How fast was the moving car going?

Answer 1

The change in observed frequency as an observer moves toward or away from a stationary source of sound is called the Doppler effect.

Step-by-step explanation:

The observed change in frequency as an observer moves toward or away from a stationary source of sound is known as the Doppler effect. It occurs due to the compression or expansion of sound waves as the source and observer move relative to each other. When the observer is moving towards the source, the frequency of the sound heard is higher than the actual frequency of the source. Conversely, when the observer is moving away from the source, the frequency of the sound heard is lower than the actual frequency of the source.