
Given Information:
Index of refraction of glass = n₂ = 1.42
Angle of reflection = θ₁
Angle of refraction in terms of angle of reflection = θ₂ = 0.5θ₁
Required Information:
Angle of refraction = θ₂ = ?
Answer:
Angle of refraction = θ₂ = 44.76°
Explanation:
We know from the Snell's law that
n₁sinθ₁ = n₂sinθ₂
Where n₁ is index of refraction of air and n₂ is index of refraction of glass, θ₁ is the angle of reflection and θ₂ is the angle of refraction.
Assuming n₁ = 1
1*sinθ₁ = 1.42*sinθ₂
since θ₂ = 0.5θ₁
1*sinθ₁ = 1.42*sin0.5θ₁
1/1.42 = sin0.5θ₁/sinθ₁
sin⁻¹(1/1.42) = sin⁻¹(sin0.5θ₁/sinθ₁)
44.76° = 0.5θ₁
θ₁ = 44.76°/0.5
θ₁ = 89.52°
So the angle of refraction is
θ₂ = 0.5(89.52°)
θ₂ = 44.76°