A light ray travels from water (n = 1.33) to crown glass (n = 1.52) and bends at a 30º angle to the normal.

What is the incident angle for the light from the water? Answer with three significant digits.

**I tried Snell's Law and no matter what I do, I didn't get the correct answer, help me :(

Question

A light ray travels from water (n = 1.33) to crown glass (n = 1.52) and bends at a 30º angle to the normal.
  
What is the incident angle for the light from the water? Answer with three significant digits.

**I tried Snell's Law and no matter what I do, I didn't get the correct answer, help me :(

theeric · Answer

It seems like you have all the information for Snell's Law!|dw:1397869962800:dw|
$n_w\sin\theta_w=n_g\sin\theta_g$
$\implies \theta_w=\arcsin\left(\dfrac{n_g\sin\theta_g}{n_w}\right)$

theeric · Answer

|dw:1397870541728:dw|
That doesn't seem too bad :) What are you getting?

theeric · Answer

Good luck! If you're using a calculator, make sure you have it set to degrees!