일반물리학 2 — Electromagnetic Waves: Problem 25

25 In Fig. 33-40, a ray of light is perpendicular to the face $ab$ of a glass prism ($n = 1.81$). Find the largest value for the angle $\phi$ so that the ray is totally reflected at face $ac$ if the prism is immersed (a) in air and (b) in water.