(a) When the speaker diaphragm moves outward, it creates a condensation. (b) When the diaphragm moves inward, it creates a rarefaction. The condensation and rarefaction on the Slinky are included for comparison. In reality, the velocity of the wave on the Slinky v
Slinky is much smaller than the velocity of sound in air v. For simplicity, the two waves are shown here to have the same velocity.

Figure 16.12 (a) When the speaker diaphragm moves outward, it creates a condensation. (b) When the diaphragm moves inward, it creates a rarefaction. The condensation and rarefaction on the Slinky are included for comparison. In reality, the velocity of the wave on the Slinky v _Slinky is much smaller than the velocity of sound in air v. For simplicity, the two waves are shown here to have the same velocity.