Perspex has a greater refractive index than ice. Explain what happens to the speed and direction of a ray of light at it travels from ice into Perspex. Thanks!

when the ray passes from ice to perspex it must approach the normal

Explanation:

This is an exercise in refraction of light, the process is governed by the expression

      n₁ sin θ₁ = n₂ sin θ₂

where we use index 1 for the incident medium and subscript 2 for the scattered medium.

In our case, medium 1 is ice with the lowest refractive index.

           sin θ₁ = n₂ / n₁   sin θ₂

To fulfill this equation, if the ray travels through the medium 1 ice with an angle θ₁, the angle in the medium 2 perspex must be smaller so that the sine is smaller, so when the ray passes from ice to perspex it must approach the normal

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