Doppler Effect

When an automobile moves towards a listener, the sound of its horn....

• you need to know the kind of car before this can be answered

• seems to decrease in pitch

• seems to increase in pitch

• nothing seems to happen to the pitch; Doppler effect refers to volume changes

True / False: A higher frequency results when a wave source moves towards an observer.

• True

• False

When the automobile moves away from the listener, what seems to happen to the sound of the automobile?

• nothing because the Doppler Effect refers to changes in volume not pitch

• seems to decrease in pitch

• seems to increase in pitch

• the make of the car needs to be known before this can be answered

As a sound source approaches a listener the wavelengths compress therefore the frequency _____ and pitch _______

• increases, decreases

• decreases, decreases

• increases, increases

As a sound source moves away from listener, the wavelengths ___________

• stays the same

• compresses

• spread out