A.) Sunlight strikes a piece of crown glass at an angle ofincidence of 31.5deg. Calculate the difference in the angle ofrefraction between a yellow (580 nm) and a violet (410 nm) raywithin the glass. The index of refraction is n=1.523 for yellow andn=1.538 for violet light. You have to calculate the angle ofrefraction for both light rays (they have different indices ofrefraction). You are looking for the difference of theseangles.
B.) The ray now travels inside the glass. What is the minimumangle of incidence at which the yellow ray can hit the surface ofthe glass and become there totally internally reflected and notrefracted? The angle of incidence is the angle with respect to thenormal. Now the beam comes from inside and wants to leave themedium. Since the index of refraction of the medium is larger than1 (index of refraction of air) there is a critical angle at whichthe beam is totally internally reflected.
