# Index of refraction of the material

diredragon

## Homework Statement

A laser is fired into a wet paper placed ontop of a glass plate of thickness ##d## and an angle of ##0## degrees. When the light hits the paper and goes through the plate it forms a circle of light of radius ##R##. What is the index of refraction of the glass plate?

## Homework Equations

3. The Attempt at a Solution [/B]
Apperently the answer is ##\frac{\sqrt{R^2+d^2}}{R}##. When the light hits the paper it bursts kind if...and forms a cone which base is the circle formed at the end but how was this proportion made. Its the ##\frac{1}{sinx}## where ##sinx## is the sine of te entry angle