Adoppler effect occurs when a source of sound moves. true or false

The Doppler effect refers to the change in a wave perceived frequency when the emitter of the waves, and the receiver (or observer in the case of light) move relative to each other.

In other words, it is the variation of the frequency of a wave due to the relative movement of the source of the wave with respect to its receiver.

It should be noted that this effect  bears its name in honor of the Austrian physicist Christian Andreas Doppler, who in 1842 proposed the existence of this effect for the case of light in the stars. Another important aspect is that the effect occurs in all waves (including light and sound). However, it is more noticeable to humans with sound waves.

the journeys of marquette, joliet and la salle a) new france expand.

all three of these explorers explored the midwest and the area around the great lakes, which they subsequently claimed for france.

this was a big portion of territory and expanded new france which before then only consisted of quebec province in northeastern canada