What does Snell's Law describe in relation to sound?

Snell's Law is fundamentally concerned with the behavior of waves, including sound waves, as they travel from one medium to another. The principle states that when a wave passes from one medium into another (e.g., from air into water), the angle at which it travels changes according to the properties of the two media involved. Specifically, it relates to how the speed of sound changes due to differences in the density and elasticity of the two materials.

The correct answer emphasizes that sound waves will bend, or refract, when they enter a medium where the speed of sound is different. This bending behavior leads to the phenomenon where sound might travel faster or slower depending on the media it moves through, which is consistent with the direction of sound propagation and its changing speed across different mediums. Essentially, Snell's Law mathematically defines this relationship through the proportion of the sines of the angles of incidence and refraction and the velocities of sound in the two media.

In contrast, while some of the other choices may mention angles or direction, they do not encapsulate the essential concept of refraction due to changes in medium density as described by Snell's Law. The focus should remain on how sound behaves when it passes through boundaries between different materials, which is