Refraction and Snell's Law - IB Physics

Proof of Snell's Law using calculus:

[tahazamankhankhattakmbgy]

You are an amazing person I was failing physics and then I got a 6 cuz of you Thanks you truly have been sent by god for IB Physics Students

[Oscar-osfj]

shouldn't the answer to the example question of refraction & snells law be 8.7×10^(8), not 5.7×10^(8), because nglass is 1.66, making C/nglass=1.8×10^(8), not 2.25×10^(8)? You seemed to have used 1.33 as nglass, which is the refraction index of water.

[hqppyfeet]

For the Snell's Law example, I plugged the numbers into (sinθ_1*V_2)/V_1 = sinθ_2, and I got θ_2=19.88, which can be rounded to 19.9, similar to your answer. Is this a better way of solving these type of questions?

[bed]

i think you solved the example at minute 8 wrong. you used the refraction index of the water to get the velocity of the light in glass.