Question

Using Snell’s Law
A 2 column by 7 row table. Column 1 is titled Material and contains the following entries: Air, Water, Quartz, Lucite, Zircon, Diamond. Column 2 is titled Index of Refraction and contains the following entries: 1.003, 1.33, 1.46, 1.50, 1.92, 2.42.
An incident ray strikes a boundary at a 72.5-degree angle, resulting in an angle of refraction of 39.6 degrees. The index of refraction of the first medium is 1.0003.

What is medium 1?


What is medium 2?

Answer 1

Use Snell’s law: n1 sin θ1 = n2 sin θ2, so n2 = n1 sin θ1 / sin θ2.

n1 = 1.0003, θ1 = 72.5°, θ2 = 39.6°.

sin 72.5° ≈ 0.95372, sin 39.6° ≈ 0.63740

n2 ≈ 1.0003 × 0.95372 / 0.63740 ≈ 1.498 ≈ 1.50

Medium 1: Air (n ≈ 1.0003, listed as 1.003 in the table)
Medium 2: Lucite (n ≈ 1.50)