Question

2. When a fire truck moves away from you, you hear the pitch of the siren go down. This is

because of
(10 Points)
resonance
beats
harmonic
the Doppler effect

Answer 1

Doppler is correct

an increase (or decrease) in the frequency of sound, light, or other waves as the source and observer move toward (or away from) each other. The effect causes the sudden change in pitch noticeable in a passing siren

Answer 2

the Doppler effect. (I don't know how to explain it lol)