A ray is incident on a sheet of transparent material by parallel sides. The angle of incidence is 60° and the thickness of the sheet is t = 1.40 cm. As the ray passes during the sheet, it is displaced x = 0.650 cm from its original direction of motion. What is the index of refraction of the sheet? (Hint: Use geometry to write two separate expressions for z, the distance that the ray travels during the sheet. Eliminate z from these two equations to get an equation in which the only unknown is the refracted angle. )