Integrated Physics and Chemistry - Unit 10: Waves Doppler Effect
In this lesson, you learned about the Doppler effect. The Doppler effect is the apparent change in frequency perceived when the source of a sound and an observer are approaching or moving away from each other. As a sound moves away from you, the observed wavelengths become longer, creating a lower-pitched sound. As a sound moves towards you, the observed wavelengths become shorter, resulting in a higher-pitched sound.
The Doppler effect occurs when an object moves at a subsonic speed, or slower than its own sound waves. If an object moves at a supersonic speed, or faster than the speed of its sound waves, a shock wave forms and observers hear a sonic boom.