A ray of light is incident on a flat surface of a block of polystyrene, with an index of refraction of 1.49, that is submerged in water. The ray is split at the surface, where the angle of refraction of the transmitted ray is 19.1°. What is the angle of reflection (in degrees) of the reflected ray?

21.5°

Explanation:

Given,

Refractive index of water, n₁ = 1.33

Refractive index of polystyrene, n₂ = 1.49

Angle of reflection = ?

Angle of refraction = 19.1°

Using Snell's law

n₁ sin θ₁ = n₂ sin θ₂

1.33 x sin θ₁ = 1.49 x sin 19.1°

sin θ₁ = 0.366

θ₁ = 21.5°

According to law of reflection angle of incidence is equal to angle of reflection.

Angle of reflection = 21.5°