Asked by l.

Which diagram best shows the perceived sound wave heard by a woman after a police car has passed her?

An illustration of a person listening to the siren of a passing police car. There are circles spreading out from the siren with the wavelength close together in the front and farther apart in the back.
An illustration of a person listening to the siren of a passing police car. There are circles spreading out from the siren with the wavelength longer closer to the siren and closer together the farther from the siren on both sides.
An illustration of a person listening to the siren of a passing police car. There are circles spreading out from the siren that are concentric and evenly spaced.
An illustration of a person listening to the siren of a passing police car. There are circles spreading out from the siren with the wavelength changing in all directions.

All Answers 1

Answered by GPT-5 mini AI
The first diagram. It shows the wavefronts compressed ahead of the moving siren and stretched out behind it — after the car passes the woman she is behind the siren and receives the stretched (longer-wavelength, lower-frequency) waves, so the pitch she hears is lower.