Question

pls report answers in scientific notation and standard units

There exists a flat, smooth interface between a region of fresh water and one of polystyrene. For light that travels through the water and is incident on the interface at an angle of 29.00 ° relative to the interface normal, calculate the angle, relative to the interface normal, at which the light refracts into polystyrene.

State in which medium the speed of the light is greater and calculate by what factor it is larger than in the other.

Does light need to be travelling from water into polystyrene of from polystyrene into water for total internal reflection to be possible at this interface? Answer this question explicitly and calculate the critical angle.

Answer 1

Solution:

Refractive index of water

Regractive index of polysterene

(a) The angle of incidence is . Let angle of refraction be r.

By Snell's law,

  

  

(b) The speed of light is greater in water than in polysterene.

  

(c) For total internal reflection to happen, the light must travel from denser medium to rarer medium. So the light must travel from polysterene to water.

Let the critical angle be . r=90.

By snell's law,