Which law governs the relationship between incident and transmission angles and the speeds of sound in the media?

• A. Hooke's law
• B. Snell's law
• C. Ohm's law
• D. Pascal's law

Answer: (B)

Waves refracting at a boundary between two media are governed by Snell's law, which ties the incident angle, the transmitted angle, and the speeds of sound in the two media together. Because the wave’s frequency stays the same across the boundary and the boundary imposes a continuous parallel component of the wavefront, the relationship sin(angle_in) / v1 = sin(angle_out) / v2 holds. In practical terms, if the second medium is faster for sound, the transmitted ray bends away from the normal; if it’s slower, it bends toward the normal. This framework specifically explains how incident and transmission angles relate to the speeds of sound in the respective media.

Other laws describe different phenomena: Hooke's law deals with elastic deformations, Ohm's law with electrical currents, and Pascal's law with pressure transmission in fluids. They don’t address how wave directions change when crossing boundaries.