A prism is made from a piece of glass with a triangular cross-section. The angles of the triangle are 90, 45, and 45. As shown schematically in the figure below, the beam of light enters the glass perpendicular to the long side of the triangle, and is then internally reflected off the back wall of the prism, and again totally internally reflected from the bottom wall of the prism, before re-emerging from the long side of the prism.
a. Determine the angle between the incoming and the outgoing light beams.
b. If the prism is surrounded by air (n=1), what is the minimum index of refraction of the glass for the total internal refraction to happen?
