Light moves from flint glass (n = 1.66) into water at an angle of incidence of 26.0°.
a) What is the angle of refraction?
Answer in units of º.
b) At what angle would the light have to be
incident to give an angle of refraction of 90.0°
Answer in units of º.

Explanation:

Through Snell's Law, we can solve this.

The formula is:

n1 * sin(theta1) = n2 * sin(theta2)

n1 = flint = 1.66

n2 = water = 1.33

theta1 = 26.0°

theta2 = angle of refraction

Substituting these values in the formula,

1.66 * sin(26) = 1.33 * sin(x)

[1.66 *sin(26)] ÷ 1.33 = sin( x )

0.5471 = sin(x)

arcsin(0.5471) = x

33.17 = x

Therefore, the angle of refraction is 33.17°

b.) Using the same formula, we have:

1.66 * sin(x) = 1.33 * sin(90)

sin(x) = [1.33 * sin(90)] ÷ 1.66

sin(x) = 0.8012

x = arcsin(0.8012)

x = 53.2453°

Therefore, the light needs to have an angle of incident of 53.2453° in order to have a 90° angle of refraction.

volume: 22

density: 7.04