# Homework Help: Finding index of refraction using wavelength and 2 angles?

1. Oct 28, 2008

### maxfails

Finding index of refraction using wavelength and 2 angles??

I'm not sure how to do a problem that involves a light ray striking a block/air interface, how to find the index of refraction of a transparent material when given the wavelength, the angle the light ray makes with respect to the normal when it enters and when it exits.

It's worded like this.

Model the following problem:
A light ray of wavelength (lambda) propagates in a transparent block of material and strikes a block/air interface at q1 to the normal When it emerges into the surrounding air it makes a q2 angle with the normal. What is the index of refraction of the material?

It is actually a programming assignment but that's not important now I'm just not sure which formulas (I'm sorry but formulae just looks and sounds way too nerdy) to use.
Because the question gave 3 variables I am assuming you need to involve all 3 of them in the calculation of the index of refraction, n. I was thinking you could use Snell's law since from what i remember the index of refraction of air is constant. But then what is the point of the wavelength?

2. Oct 28, 2008

### Staff: Mentor

Re: Finding index of refraction using wavelength and 2 angles??

Look up Snell's law of refraction: Snell's Law

3. Oct 28, 2008

### Staff: Mentor

Re: Finding index of refraction using wavelength and 2 angles??

It's not unusual for exercises to give more information than is actually needed for the solution. This is to give you practice in distinguishing between relevant and irrelevant information.

4. Oct 28, 2008

### maxfails

Re: Finding index of refraction using wavelength and 2 angles??

yea but the thing is, its not just some small exercise its actually a major assignment involving making a model in a program and creating a procedure to calculate is, so I'm not sure if they would give extra info on something like this.

guess i'll email the prof or something...