The speed of the light in a clear plastic is 1.90x10^8 m/s. A ray of light enters the plastic at an angle of?

22 degrees. At what angle is the ray refracted?The speed of the light in a clear plastic is 1.90x10^8 m/s. A ray of light enters the plastic at an angle of?
The index of refraction n in a medium is equal to c/v, where c is the vacuum speed of light, and v is the speed of light in the medium. That gives the plastic an index of n = 3.00/1.90.





By Snell's law, n2/n1 is also the ratio (sin θ₁)/(sin θ₂), where θ₁ is the angle of incidence in the medium with index n1 and θ₂ is the angle of incidence in the medium with index n2. So:





θ₂ = arcsin(n1*(sin θ₁)/n2)





You have n1 = 1.00 for air and n2 = 3.00/.190 for the plastic and the rest is easy.