Question

make a prediction

1. observe the distance

between the compressions
shown in the image. what
do you notice about the
wavelengths behind and in
front of the ambulance?
what do you predict will
happen to the wavelengths
as the ambulance begins
moving to the right?

type your answer here.

Explanation:

First, observe the static ambulance: the wave crests (compressions) are evenly spaced, so wavelengths in front and behind are equal. When the ambulance moves right, it travels toward the waves it emits in front, compressing those wave crests closer together. It moves away from the waves behind, stretching those crests farther apart. This is the Doppler effect for sound waves.

Answer:

1. When the ambulance is stationary, the wavelengths in front of and behind the ambulance are equal (the distance between each compression is the same on both sides).
2. When the ambulance begins moving to the right:

• The wavelengths in front of the ambulance will become shorter (compressed closer together).
• The wavelengths behind the ambulance will become longer (stretched farther apart).