In: Physics
I shine a polarized laser at a piece of clear plastic. I rotate the plastic, changing the angle that the laser strikes the plastic, until there is no light reected o of the plastic. Then I measure the angle of the light relative to the normal of the plastic and I nd it to be 61:2. What is the index of refraction of the plastic? (The laser beam is traveling in air with an index of refraction of 1 before it enters the plastic.)
when angle of incidence is 61.2 degree, there is no
refraction.
61.2 degree is critical angle for total internal reflection
At this angle of incidence, angle of reflaction is 90
degree
n = 1/sin 61.2
= 1.14
Answer: 1.14