Question

A beam of light travels in air and then passes through a piece of glass at an angle of 45 degrees to the normal. As the light passes from the air into the piece of glass, the light ray is bent, what is the angle of refraction measured from the normal?

Answer 1

The angle of refraction measured from the normal is approximately 28.13°

Step-by-step explanation:

The angle of refraction is the angle made by the refracted ray and the normal line drawn at the point where the ray passes through the interface of the two mediums

According to Snell's law, we have;

`_1 n_2 = (n_1)/(n_2) = (sin \, \theta _2)/(sin \, \theta _1)`

n₁·sin (θ₁) = n₂·sin(θ₂)

Where;

₁n₂ = The refractive index of air to glass = 1.5

n₁ = The refractive index of air = 1

n₂ = The refractive index of glass ≈ 1.5

θ₁ = The angle of incidence = 45°

θ₂ = The angle of refraction measured from the normal

Therefore, we have;

1/1.5 = sin(θ₂)/sin(45°)

sin(θ₂) = sin(45°)/1.5 = (√2)/2/(3/2) = (√2)/3

∴ θ₂ = arcsin((√2)/3) ≈ 28.13°

The angle of refraction measured from the normal = θ₂ ≈ 28.13°.