A diver shines light up to the surface of a flat glass-bottomed boat at an angle of 30° relative to the normal. If the index of refraction of water and glass are 1.33 and 1.5, respectively, at what angle (in degrees) does the light leave the glass (relative to its normal)?
A) 26
B) 35
C) 42
D) 22
E) 48

Question

Quizplus · Accepted Answer

Using Snell's Law, n1 * sin(theta1) = n2 * sin(theta2), where n1 = 1.33 (water), theta1 = 30°, n2 = 1.5 (glass). Solving for theta2 gives sin(theta2) = (1.33/1.5) * sin(30°) = 0.4433. Thus, theta2 ≈ 26.3°. Then, applying Snell's Law again for glass to air (n = 1), we find the angle in air to be approximately 42°.

A Diver Shines Light Up to the Surface of a Flat