Question

As a train rushes away from a crossing, the pitch of its horn goes down because _____________________.

a sound waves get farther apart as the source of the sound moves closer
b sound waves get farther apart as the source of the sound moves away
c sound waves get closer together as the source of the sound moves away
d sound waves stay the same distance from each other as the source of the sound moves away

Answer 1

The awnser is b

Step-by-step explanation:

The sound waves get smaller as the sound moves farther away, and since the sound waves are smaller, the sound is quieter. This is known as the Doppler effect.