Laser Beam and index of refraction

[skibum143]

Homework Statement

A laser beam enters a 10.0cm thick glass window at an angle of 30 degrees from the normal. The index of refraction of the glass is 1.46. At what angle from the normal does the beam travel through the glass?

Homework Equations

sin theta 1 / sin theta 2 = n1 / n2 = v1 / v2

The Attempt at a Solution

sin (30) / sin theta 2 = 1 / 1.46
theta 2= 46.89 degrees

Not sure what I'm doing wrong here? I also tried 90 deg - 46.89 = 43.11 deg but that was also wrong.

 

[ideasrule]

Homework Equations

sin theta 1 / sin theta 2 = n1 / n2 = v1 / v2

No, sin theta 1 / sin theta 2 = n2 / n1. You can also remember it as n1*sin(theta1)=n2*sin(theta2), which I find easier to use.

 

[skibum143]

Ah, I see. Thank you!