Question

The speed of light in a material is 0.50

c. what is the critical angle of a light ray at the interface between the material and a vacuum?

Answer 1

30 degrees

Explanation: First, what is the critical angle? Critical angle is the angle from the normal, at which light enters another medium, which causes the reflected light to reflect at an angle of 90 degrees.

Using Snell's Law:

critical angle = sin^-1(n2/n1)

n2 = c/v. In a vacuum this = 1

n1 = c/.5c = 2

critical angle = sin^-1(1/2)=30 degrees

Answer 2

Step-by-step explanation:

This problem indicates that the speed of light in a material medium is 0.5 10⁸ m / s, they ask to find the critical angle between the material and the vacuum

Let's find the refractive index of the material

n = c / v

n = 3 10⁸ / 0.5 10⁸

n = 6

When the material passes from one medium to another, it must comply with the law of refraction

n₁ sin θ = n₂ sin θ₂

for the angle criticize the angles tea2 = 90

tea = sin⁻¹n₂/ n₁

The vacuum replacement index is n₂ = 1

tea = sin⁻¹ (1/6)

tea = 9.59º