# Problem: A beam of light in air is incident upon a stack of four flat transparent materials with indices of refraction 1.20, 1.40, 1.32, 1.28. If the angle of incidence for the beam on the first of the four materials is 60°, what angle does the beam make with the normal when it emerges into the air after passing through the entire stack?

###### FREE Expert Solution

Snell's law:

$\overline{){{\mathbf{\eta }}}_{{\mathbf{1}}}{\mathbf{s}}{\mathbf{i}}{\mathbf{n}}{{\mathbf{\theta }}}_{{\mathbf{1}}}{\mathbf{=}}{{\mathbf{\eta }}}_{{\mathbf{2}}}{\mathbf{s}}{\mathbf{i}}{\mathbf{n}}{{\mathbf{\theta }}}_{{\mathbf{2}}}}$

When the light is incident on the first transparent material we have:

ηsin(i) = η1sinθ1

Between the first and the second transparent materials:

η1sinθ1 = η2sinθ2

90% (295 ratings) ###### Problem Details

A beam of light in air is incident upon a stack of four flat transparent materials with indices of refraction 1.20, 1.40, 1.32, 1.28. If the angle of incidence for the beam on the first of the four materials is 60°, what angle does the beam make with the normal when it emerges into the air after passing through the entire stack?