Question

A longitudinal wave is shown.

An illustration of a horizontal spring. In the spring are areas where the rings are closer together and areas where the rings are further apart. The area where the rings are closer together is labeled A, the area where the rings are further apart is labeled B, the height of the spring is labeled C and the distance between adjacent areas where the rings are closer together is labeled D.
Which label identifies a rarefaction?

A
B
C
D

Answer 1

B — a rarefaction is a region of lower density/pressure where the spring coils are spread apart.