Total internal reflection | Geometric optics | Physics | Khan Academy
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- เผยแพร่เมื่อ 8 ธ.ค. 2010
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Critical incident angle and total internal reflection. Created by Sal Khan.
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i love how he hopes we find it "reasonably interesting," lol. not "incredibly" interesting or even "very" interesting. just "reasonably" interesting. :D
@Enrique Duran Mynenko yes
@Enrique Duran Mynenko You just asked me five days ago bro.
Alive?
@@omaralsaheb9737 bro 😭
Man, why cant i have teachers like this? Mine just sits there and talks like i can imagine what the .....*.... he is talking about. Thanks.
Same💔
once again, I don't know what would I do without your videos. so much love to you Mr. khan
1:26 to 2:45 is what i found most useful, thanks mate
Thank you, Mr. Khan! You are the one who helps me to escape from my boring physics lesson!
Sal, you are a lifesaver! Summer classes have us learning this whole playlist in 3 days and it's going to make up around 25% of the final. I was so stressed but 3 hours of sitting down and watching this playlist actually makes it manageable. Thank you, thank you, thank you!!!
0:38 i love that you always have such good examples to explain such phenomenons. this has actually something to do with the wave character of light. the example with the car is perfectly fitting. the light reenters the medium it just left due to its diagonal micro movements and looses speed. reentering the fast medium again, it made a curve.
I swear no one teaches like Khan Academy!
This is amazing, I had been trying to understand this whole concept from other videos, but for some reason, all those teachers or speakers assumed that everyone is a genius and automatically knows what they are talking about so instead of explaining, they just carry on saying a bunch of words that I have never had of.
Where have you been all my life *sigh*
I appreciate the analogy of the car going from one surface to another. That's an easy one to remember.
thank you so much ! I litteraly study in french and english is not my first language and i’ve learned more from this video than from class😭😭
I need my teacher teach like you,interesting and easy-understanding
This wil help me so much for my physics test tomorrow!
Thxs a million!! Khan Academy videos have been helping me for 2years now! Sal's the best at making complex things simple!!
thank you! this video better my understanding :)
Thank you SO much! This has been immensely useful and makes far more sense than it did before I watched the video! Many thanks
This was the one part of my optics subject in school i never understood. Thanks for explaining clearly!
I want to keep it simple. You do great!!
Thanks a lot. My teacher made the explanation complicated. This sums up what I need perfectly.
Once you had explained total Internal reflection, I whipped out my scale and even tried it in practical....and it worked....Thanks for explaining in ruch simple words and making it understandable
You have carried me through my GCSE's
waaay better than my teacher. I love khanacademy
My teacher has been explaining it for the past hour and I had no clue what she was saying. I understood right away after watching this video!
I found it reasonably interesting! Thanks! :3
Thanks for this video, helped explained this better rather in class. Fully understood the concept behind critical and total internal reflection. - grade 10 student
Youve helped me in so many of my classes...... i hope you know a lot of people really appreciate this stuff. Thank you. Thank you so much.
Reasoning it out, your explanation from 0:28 onwards was fantastic - it just immediately clicked. Thanks for your help!
This is great! Havin a physics test tomorrow! This really helped me to understand what TIR Is!
Cleared things up for me, thanks!
Thank u! This helps me a lot doing my school works! An amazing and engaging lesson!
Learned more in 6 minutes than an hour with my college professor... thanks so much.
Thaaanks , that was really helpful !
right through d basics ! nailed it ! Sal u rock !
The core has a high refractive index and it is surrounded by cladding that has a very low refractive index. There is a "cone of acceptance" (where you seem to have gotten confused; the air to 'glass' transition is not fundamental to internal reflexivity) such that for snells law, rearranged and sin90->1
crit. angle = sin^-1 (1 / huge n). the argument approaches 1/inf. and sin inverse of zero in 90 degrees.
That is to say, that only if light approaches at 90 angle will it escape. :3!
Thank you SO MUCH!!!! This helped to explain the concept and reasoning of the critical angle.
This makes so much more sense!
Thank you so much!! It all makes sense now!
i love your voice and teaching skills Sal, thank you so much for taking the time to make these wonderful videos you are awesome
Great video for understanding reflection,refraction and critical angles!
helps me alot. thanks!
Thx!!! This helps so much I hope I wont fail my physics exam
Thanks a lot for this video! It's nice to see you're constantly uploading lots of videos. Many of them are so helpful! Thank you so much for keeping this channel up and going.
These videos are the only reason that I'm able to pass my physics exam.. THANK YOU SO MUCH!
Thank you Khan Academy... You guys are always life savers !
helped me out alot. Thank you.
The way u explain is top man 👌👌
Oh my God, they never told us where the 1 comes from!! Thanks a lot! ^^ You're so awesome! :D
That's a great programme...
It helps me a lot!!!
Thanks a lot..!! It was very helpful 😁..
Thank you ，that was really helpful
Thank you so much, you really helped me for my test!
Thank you SO much for this!!!!
This is awesome explanation!
you are a GENIUS! Thanks alot
Thank you Mr.Khan ,your videos are very helpful .
You're a life saver Mr. Khan. Now I know I won't fail my physic exam.Lots of love 💜
This video helped alot!!!!
bless you sal
Thanks you very much for the video I was facing trouble understanding total internal reflection...... Thanks a lot
Thank you so much, you made this waaaaay easier
Respect🙌🙌
what a concept of fiber optics wow amazing thanx alot
thanks, this helped alot
Nailed it.awesome explanation
This is awesome!
well explained
Thank you sir!!!
thank you! It only takes me 8 mins to understand what total internal refraction is. I can't even figure out what my teacher is teaching before watching this video.
Most beautiful channel i have ever seen.❤
The best explanation ❤️👏
The car example was brilliant
Thank you so much
You explained it very well sir :D
thank you so much was very halpful😉
Sooooooooo helpful, my exam is tomorrow and this is really going to help
Sal Khan is the GOAT🐐
Thank You
this guys a champion
thanks a lot!
I love this guy's calculator 😍
Nice explanation 👌
sir you just saved my life
Man ,you are awesome
super AmaZing.....I'd rather bunk college and sit at home and learn from you......You"re amazing!!
So is it safe to assume that regardless of the media the ray is initially in and the final media it is in, we can use the media with the lower index of refraction in the numerator, and the higher index in the denominator? Because there's been a couple situations where I get undefined errors in my calculator. For example when a ray goes from glass to air and I use the glass in the numerator and the air in the denominator because I'm thinking n1 = glass since it was in glass first.
7:24 is a glitch in real life
3:29 also glitch
7:39 another one!
thank you so much, man. my teacher has such a strong German or Austrian accent and its hard to understand anything thanks so much
thank you so much,you are the best Physics teacher in the entire world!! by a student from HONG KONG
nice sal.
This really helped a lot, I'm 14, i need to learn this in foreign German though :c this is going to be so hard xD
NZVON where did you come from?
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woah
Thank u
Superb
Too good
very good . Thank you so much.May Lord bless you
"Light thats coming out of the color." hahaha Love you khanacademy
In our case -1 ≤ a ≤ 1 and b ≥ 1. And so, -1 ≤ a/b ≤ 1.
اشاهد هذا الفيديو عام 2022 ومر عليه 12 عام . اتمنى من يقرأ هذا التعليق يترجمة ويفكر في تعلم اللغة العربية لأنها رائعة
Good
Amazing , just amazing 👌🏻👌🏻👌🏻😬😬😬
THANK YOU THANK YOU THANK YOUUUUUU
Is this what causes all reflection? Do mirrors, for example, have such high refractive indexes that they reflect all light?
That is a very good question