Determine the angle of refraction of a ray of light that passes from water to air, falling at an angle of 45.

Since from Snell’s law the angle of incidence of light on the surface is related to the angle of refraction by the ratio:
nin * sinα = nair * sinβ, then
sinβ = nwater * sinα / nair, where nwater / nair = n is the relative refractive index of the two media (for water nwater / nair = 1.333), α is the angle of incidence of the light beam (β = 45º).
sinβ = n * sinα = 1.333 * sin45º = 1.333 * 0.707 = 0.942431.
Using the Bradis table, we calculate the angle of incidence of the light beam: β ≈ 70º.
Answer: The angle of refraction of the light beam is 70º.