1. The problem statement, all variables and given/known data Given a three layer model ------------------------------------------------- [tex]v_1=1.5[/tex]km/s ------------------------------------------------- [tex]v_2=1.3[/tex]km/s ------------------------------------------------- [tex]v_3=2.0[/tex]km/s Assume a ray goes through layer 1 and hits the interface between layer 1 and layer 2. What is the critical angle? 2. Relevant equations Snells law [tex]\frac{\sin \theta_1}{\sin \theta_2}=\frac{v_1}{v_2}[/tex] 3. The attempt at a solution To find the critical angle, you normally take [tex]\sin \theta_c = \frac{v_1}{v_2}=\frac{1.5}{1.3}[/tex]. But in this case that means I have to take [tex]\sin^{-1}[/tex] of a value that is over 1! How do I solve this?
When I look up Snell's law on Wikipedia it says [tex] \frac{\sin \theta_1}{\sin \theta_2}=\frac{v_1}{v_2}=\frac{n_2}{n_1} [/tex] Why does the subscript change in the [tex]n_n[/tex] ? Isnt [tex]v_1=n_1[/tex] and [tex]v_2=n_2[/tex]? Thanks for answering
According to the definition, refractive index n = c/v. where c is the velocity of light in vacuum and v is the velocity in the refracting medium. So v = c/n Or v1 = c/n1 and v2 = c/n2 then v1/v2 = .....?