What is Snell's Law used for?

Snell's Law is fundamentally used to relate the angles of incidence and refraction when a wave, such as light, passes from one medium to another. This principle is crucial in understanding how waves change direction due to the differing speeds at which they travel in different materials. According to Snell's Law, the ratio of the sines of the angles of incidence and refraction is equivalent to the reciprocal of the ratio of the velocities of the wave in the two media. This law is key in various applications, including lenses, prisms, and other optical devices, allowing for precise control of light behavior.

In contrast, reflecting angles of waves or wave behavior encountering barriers relate to different principles of wave mechanics, and measuring the speed of sound involves distinct methodologies not directly tied to Snell's Law.