Philip P. answered 03/07/14
Tutor
4.9
(484)
Effective and Patient Math Tutor
This is an application of Snell's Law:
n*sinθ = n'*sinθ'
where:
n = the index of refraction of the initial medium (air in this case)
n' = the index of refraction of the final medium (Lexan glass)
θ = the angle of the incident light beam (45o)
θ' = the angle of the transmitted light beam (in the glass)
You know n, n', and θ. Solve for θ'
Note that the angle is measured from the line normal to the surface.