Question

A police car is rapidly approaching you at a stop light. Explain what happens to the frequency of the sound as the police car draws closer. What do you hear?

Answer 1

When the police car is moving towards you, the sound waves are more compressed together, leading to a higher pitch sound. This is according to the Doppler Effect, in which sound waves ahead of the object is more compressed, leading to a higher pitch, and more spread out behind, leading to a lower pitch.

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