Chapter 33, Problem 50P

In Fig. 33-50a, a beam of light in material 1 is incident on a boundary at an angle θ₁ = 40°. Some of the light travels through material 2, and then some of it emerges into material 3. The two boundaries between the three materials are parallel. The final direction of the beam depends, in part, on the index of refraction n₃ of the third material. Figure 33-50b gives the angle of refraction θ₃ in that material versus n₃ for a range of possible n₃ values. The vertical axis scale is set by θ_3a = 30.0° and θ_3b = 50.0°. (a) What is the index of refraction of material 1, or is the index impossible to calculate without more information? (b) What is the index of refraction of material 2, or is the index impossible to calculate without more information? (c) If θ₁ is changed to 70° and the index of refraction of material 3 is 2.4, what is θ₃?

Figure 33-50 Problem 50.