AP Physics 2 / Unit 14: Waves, Sound, and Physical Optics
14.5 The Doppler Effect
Notes
When a source and observer move toward each other, the observed frequency is higher; moving apart, lower.
- Applies to sound and light (redshift and blueshift).
Practice
An ambulance approaches you. The siren's pitch sounds:
Waves bunch up.
Light from a galaxy moving away from us is:
Longer wavelength.
The Doppler effect changes the observed:
Perceived pitch.
Ready for more? Take the Unit 14 test.