finding the index of refraction

[smashyash]

1. The problem statement, all variables and given/known data

I'm not sure if this can be answered without the picture but I can't get it posted.
The problem gives theta(incident) and theta(r). It's a basic refraction through a transparent plastic piece. It askes for the index of regraction of this material.

2. Relevant equations

ni * sin(theta,i) = nr * sin(theta,r)

3. The attempt at a solution

I figured since the don't give any more information that the ni value = 1 because it's assumed to be air. So I tried nr = ni * sin(theta,i)/sin(theta,r)
but this is not right...

[tiny-tim]

hi smashyash! :smile:

(have a theta: θ and try using the X2 icon just above the Reply box :wink:)
I figured since the don't give any more information that the ni value = 1 because it's assumed to be air. So I tried nr = ni * sin(theta,i)/sin(theta,r)
but this is not right...

that looks right …

without seeing the diagram, i'm guessing that either your i and r are the wrong way round, or one or both of your θs are measured from the surface instead of from the normal :smile: