Question

Light traveling in air is incident on a pane of glass (n = 1.6) at an angle of 25 degrees relative to the normal. What angle relative to the normal will it have once it is inside the glass?

Answer 1

$$n = \frac{\sin(i)}{\sin(r)}$$ $$1.6 = \frac{\sin(25)}{\sin(r)}$$ $$r=\sin^{-1}(\frac{\sin(25)}{1.6})$$

Thus, i = 15.3 degrees.