Assertion: doppler effect | /r/HasProperty | constant relative motion
Facets:
value: between observer
type: TRANSITIVE-OBJECT
value: between the source
type: LOCATION
Source sentences:
text: The Doppler Effect is caused when the source of a waveform—such as sound or light—sends out waves at a regular rate or frequency, but there is a constant relative motion between the source and observer, causing the observed frequency to change.