Snell's law example 2 | Geometric optics | Physics | Khan Academy

Snell's Law Example 2. Created by Sal Khan.

Physics on Khan Academy: Physics is the study of the basic principles that govern the physical world around us. We'll start by looking at motion itself. Then, we'll learn about forces, momentum, energy, and other concepts in lots of different physical situations. To get the most out of physics, you'll need a solid understanding of algebra and a basic understanding of trigonometry.

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[iMusikkForeva]

Sal is a gift from God to us stressed students!

[RyanBucao]

double lesson! helped me out with my math and my science exam

[nouranmahmoud]

Oh god....you are amazing .... I do understand this lesson that was really diffcult you

[afzalmohamad]

really help a lot to understand it for more complex things...
Thank you

[MelvinPaulbrains]

Sal why not give some super interesting and quite difficult problems?

[jemappellelanoosh]

Khan for noble prize :))) u r amazing thx for ur help. This wasso useful

[MrLachlan]

THANK YOU!!! My teacher has been trying to teach me this but he doesnt make it seem easy like you did. I think you will be my new physics teacher :)

[ytimg]

Thank you for doing what my lecturer and that third year uni student that runs the tutorials can't. Teach me physics.

[jamestornea]

so let me do that in a different color.... no, i wanna do it in a different color. this part made me laugh HAHAHA. Anyway I really appreciate this lesson.

[Jonnyc]

bit strange that the adjacent side is shorter than the opposite side on that diagram which clearly shows its more than half the length

[KiberMath]

That was so cool!! I love your lessons!

[LAnonHubbard]

I paused and did this problem. I found the angle which as you showed was unnecessary. I had also forgotten about a² + b² = c², so thanks for that too. I also fluffed up at the end using cosine rather than tangent but that was just stupidity LOL. Nice little problem and great explanation.

[shivshankargupta]

Sir you can take more such problem which could help me in competitive exam

[manq]

after learning basic vector trigonometry this is a scale 2 hard. learn vectors and basic trig for physics and you're good to go and of course u have to know n1sinØ1=n2sinØ2

[anhkhoinguyen]

I forgot it’s a right angle triangle, so I used the cosine law to solve for the angle of incident and I used the sine law to solve for y 💀 Took me 10 years longer than if I were to just use SOH CAH TOA. But hey, I got the right answer in the end so it doesn’t matter.

[Gringorican]

you can figure out the incidence angle (theta 1) without finding the x distance by taking the inverse cos of 1.7/8.1

[boeinglr]

@armanfazli I can understand the excitement. Its like coming first in the class!! :)

[jdavis]

What's that woman so angry about? She's got her very own laser-pointer, after all!!!! ;)

[Tomekkkk]

"this distance is" sounds funny :)

[SillyGeneva]

If it was a laser pointer...wouldn't it just bend again and go straight into the water without having an angle of refraction at all? Because a laser is just light??