C.5 Doppler Effect

Doppler Effect

The change in the observed frequency of a wave as the result of the relative motion between two bodies.

Double Doppler Effect

When a moving source produces a wave that reflects off a moving object and is received by the source again.

Spectral Lines

The wavelengths of light emitted by different elements losing electrons.

Blueshift

A decrease in the electromagnetic wavelength of light caused by the motion of an object getting closer to the observer. Shorter wavelengths of visible light are shifted towards the blue region of the visible spectrum.

Redshift

An increase in the electromagnetic wavelength of light caused by the motion of an object getting further away from the observer. Longer wavelengths of visible light are shifted towards the red region of the visible spectrum.

Moving source, stationary observer (forward)

velocity constant, frequency increase, wavelength decrease

Moving source, stationary observer (backward)

velocity constant, frequency decrease, wavelength increase

Stationary source, moving observer (forward)

wavelength constant, frequency increase, velocity increase

Stationary source, moving observer (backward)

wavelength constant, frequency decrease, velocity increase