The following discussion of Snell’s Law of Refraction (named after Willebrord Snell, 1580–1626) is needed for Problems 115–122. Light, sound, and other waves travel at different speeds, depending on the medium (air, water, wood, and so on) through which they pass. Suppose that light travels from a point A in one medium, where its speed is v₁, to a point B in another medium, where its speed is v₂. Refer to the figure, where the angle θ₁ is called the angle of incidence and the angle θ₂ is the angle of refraction. Snell’s Law, which can be proved using calculus, states that

The ratio v₁/v₂ is called the index of refraction. Some values are given in the table shown below.

A light ray with a wavelength of 589 nanometers (produced by a sodium lamp) traveling through air makes an angle of incidence of 30° on a smooth, flat slab of crown glass. Find the angle of refraction.

Transcribed Image Text:

sin 0₁ sin 0₂ V₁ V2