Chapter 33, Problem 90P

In Fig. 33-71, two light rays pass from air through five layers of transparent plastic and then back into air. The layers have parallel interfaces and unknown thicknesses; their indexes of refraction are n₁ = l.7, n₂ = 1.6, n₃ = 1.5_, n₄ = 1.4, and n₅ = 1.6. Ray b is incident at angle θ_b = 20^°. Relative to a normal at the last interface, at what angle do (a) ray a and (b) ray b emerge? (Hint: Solving the problem algebraically can save time,) If the air at the left and right sides in the figure were, instead, glass with index of refraction 1.5, at what angle would (c) ray a and (d) ray b emerge?

Figure 33-71 Problem 90.