Final answer:
The angle of refraction when a beam of unpolarized light hits a flat glass surface at an incidence of 62.1 degrees and is 100% polarized upon reflection (Brewster's angle) can be determined using Snell's Law after finding the refractive index of the glass with Brewster's Law.
Step-by-step explanation:
When a beam of unpolarized light strikes a flat glass surface at the Brewster's angle, the reflected light is 100% polarized. The Brewster's angle occurs when the angle of incidence and the angle of refraction are such that the reflected and refracted rays are perpendicular to each other. This can be described using Brewster's Law, which states that the tangent of Brewster's angle is equal to the refractive index (n) of the glass.
The angle of refraction can be found using Snell's Law:
n1sin(θi) = n2sin(θr)
Where n1 is the refractive index of air (assumed to be 1), θi is the angle of incidence, n2 is the refractive index of glass, and θr is the angle of refraction. For the given angle of incidence of 62.1°, and knowing that at Brewster's angle, the reflected light is 100% polarized, we can use the relationship tan(θi) = n2 to find the refractive index of the glass first and then apply Snell's Law to find the angle of refraction.