thats because your teacher needs to follow some rules made from the governaument, he doesn't need to do that so he explains as he wants. 5 minutes and perfection
thank you this is extremely helpful as it is so clear and concise, especially in lockdown during online learning. Keep it up, we all appreciate your efforts very much!
The one common thing between my brain and that light beam is that the knowledge going through my brain is just like that light beam going through a piece of glass. No matter what angle the knowledge hit my brain, it will still refract and change medium by going through my brain and out to the air. But, at least now I can use fancy words like refract and medium thx 2 u Cognito
For the ones curious, I leave here a explanation of why refraction happens: (It can be explained as a consequence of conservation of momentum of photons) If in medium 1 the index of refraction is n1 and in medium 2 the index of refraction is n2 and for the definition of index of refractions and wavelength we have: n1 = c / v1 , v1 = λ1 * f n2 = c / v2 , v2 = λ2 * f Dividing the above equations we obtain: n2 / n1 = λ1 /λ2 So if n2 is higher than n1, the wavelength in medium 2 is smaller than in medium 1. Now because the photon momentum is: p = h / λ Applying the conservation of momentum of the incident and transmitted photon along the parallel line of medium separation: p1 = p2 → h/λ1 *sin(θ1) = h/λ2 *sin(θ2) → n1 *sin(θ1) = n2 *sin(θ2) This is the Snell Law!! So the refraction is just a consequence of the conservation of momentum of photons!
00:06 Refraction of light waves causes change in direction. 00:51 Refraction causes waves to change speed and direction when passing through different mediums. 01:24 When light passes into a more dense medium, it bends towards the normal. 02:02 Understanding refraction of light rays in glass 02:38 Refraction occurs when waves slow down and bend towards the normal in a denser medium. 03:12 Refraction occurs as light waves bend when passing from one medium to another. 03:54 Wave speed changes during refraction 04:30 Different wavelengths of light are refracted by different amounts Crafted by Merlin AI.
thank you so much for your help!! one of the only people I actually learn and thoroughly understand from, I’m in year 10 so your support has been great for me getting ready for my gcses!
Could you maybe also create a video explaining how to calculate the refracted angle? because for my school that is needed, I don't understand how to calculate the angle because the teacher doesn't explain well especially during online classes
Sir i was afraid of waves as i was sick during the teacher taught waves and i was absent and when i looked at the book it was just diagram and they didn't teach step by step but afte watching this video all my doubts are cleared so thank you sir(i am an igcse student btw )
There is a mistake in the video description, where it says that wavelength stays the same during refraction. The video itself has the correct physics though -- frequency is unchanged, wavelength changes proportionally to the speed.
Excellent videos, but on this one the dispersion diagram towards the end is incorrect as the emergent rays refract back towards the normal rather than away. An important detail, as at IGCSE the examiners look for students to sketch and/or describe this pattern of refraction.
tysm this rlly helps i have my mocks in 2 days ty this is literally so helpful the teachers were so confusion and nobody understands her ur a lifesaver
at 4:20 you said that the frequency always stays the same and it's always the wavelength that changes but i thought that the frequency and wavelength always relate. if you have a small wavelength the frequency will be higher than a wave with a higher wavelength?
If you’d like to practise what's covered in this video, check out the lesson on the Cognito platform - cognitoedu.org/coursesubtopic/p2-gcse-aqa-h-t_4.04. The platform’s totally free, and has been built to make learning and revision as easy as possible. The main features are: - Lessons organised by topic, only the lessons relevant to your specific exam board and tier are shown. - Automatic progress tracking. Progress bars tell you what you’re doing well at, and what you need to spend some time on. - Practise quizzes so you can test your knowledge. You can quiz yourself on any combination of topics you like. - A huge number of fully-hinted questions that take you step-by-step through some of the trickiest calculations & concepts. - A comprehensive bank of past exam papers, organised both by year, and also by topic. Amadeus & Tom
Can someone explain to me 0:48 where it said "the higher the density, the slower the wave" I heard somewhere that the higher the density, the faster the wave travel since the particles would be more closely packed together, therefore it would be easier to reach by the wave
Hello, if the incident ray of white light entering a prism is combined (white), and the colours split apart by refraction causing various angles due to wavespeed within the prism, how come the emergent ray is not converted back into white light when entering back into the air? As the density is as it was originally. Thanks.
You see, what you describe would be happening inside a glass cuboid, for example. When both boundaries are parallel, one would split the wavelengths, and the second would merge the wavelengths - again giving white light. Remember this: the normals in a cuboid are parallel. Since in a triangular prism the boundaries are not parallel, the normals are not parallel. When first entering the glass, the rays are refracted and thrown apart within the glass prism. On the second side of the prism, the angle of the normal changes. The normal is perpendicular to the boundary. When moving from a dense to a less dense medium, the wave speed increases and the ray bends away from the normal. Because of the different wavelengths, on the second side the split rays are bent to different degrees a second time, further distancing them apart. This is best understood with a correct diagram. I appreciate my wording may be slightly rushed but I hope it helps you to understand!
Jesus loves u repent and believe in the GOSPEL he died to forgive ALL your sins and give u eternal life accept him before its too late JUDGMENT DAY IS COMING
The best channel to refer for biology, chemistry and physics!!!
free science lessons is
@@olliemellor1171 they both are
And maths :)
@@olliemellor1171 oof controversial
@@Cognitoedu Lmfao
i have a test tommorow and im really finding your videos helpful, thank you so much
i hope it went well :)
how was your test
When this channel disappears, it will be called incognito
bruh (sigh)
Good one
Sigh
Pink guy
😂 good one
I wish you were my teacher , mine doesn’t even teach us correctly
thats because your teacher needs to follow some rules made from the governaument, he doesn't need to do that so he explains as he wants. 5 minutes and perfection
My teacher too isnt good, but for different reasons such as no structure for the lessons and not caring to explain when people dont get it at all
My teacher should try rapping because that’s what I understood from him
us
@@MrKK-gn5mlyou guys go to public schools? ha
thank you this is extremely helpful as it is so clear and concise, especially in lockdown during online learning. Keep it up, we all appreciate your efforts very much!
Thanks La Chocolat Chaud, we appreciate the support 😁
HOT CHOCOLATE!!
Heyy Babe
i loove this channel sm, its literally saving my grades at this point. i love the aesthetic, too......
THAT'S SUCH A GREAT EXPLANATION THANKKKK YOU
Thank you for your comments and support! We really appreciate it cos it helps the videos get seen by more people 💛
U gone tho
So its incognito yeah?
The one common thing between my brain and that light beam is that the knowledge going through my brain is just like that light beam going through a piece of glass. No matter what angle the knowledge hit my brain, it will still refract and change medium by going through my brain and out to the air.
But, at least now I can use fancy words like refract and medium thx 2 u Cognito
Lol 😂😅
The joke is bad it's too long, make jokes which includes pain and hurting your self during an experiment
For the ones curious, I leave here a explanation of why refraction happens:
(It can be explained as a consequence of conservation of momentum of photons)
If in medium 1 the index of refraction is n1 and in medium 2 the index of refraction is n2 and for the definition of index of refractions and wavelength we have:
n1 = c / v1 , v1 = λ1 * f
n2 = c / v2 , v2 = λ2 * f
Dividing the above equations we obtain: n2 / n1 = λ1 /λ2
So if n2 is higher than n1, the wavelength in medium 2 is smaller than in medium 1.
Now because the photon momentum is: p = h / λ
Applying the conservation of momentum of the incident and transmitted photon along the parallel line of medium separation:
p1 = p2 → h/λ1 *sin(θ1) = h/λ2 *sin(θ2) → n1 *sin(θ1) = n2 *sin(θ2)
This is the Snell Law!!
So the refraction is just a consequence of the conservation of momentum of photons!
thanks
:)
If that’ld be that then u wouldn't be commenting here
00:06 Refraction of light waves causes change in direction.
00:51 Refraction causes waves to change speed and direction when passing through different mediums.
01:24 When light passes into a more dense medium, it bends towards the normal.
02:02 Understanding refraction of light rays in glass
02:38 Refraction occurs when waves slow down and bend towards the normal in a denser medium.
03:12 Refraction occurs as light waves bend when passing from one medium to another.
03:54 Wave speed changes during refraction
04:30 Different wavelengths of light are refracted by different amounts
Crafted by Merlin AI.
thank you so much for your help!! one of the only people I actually learn and thoroughly understand from, I’m in year 10 so your support has been great for me getting ready for my gcses!
Guys, I suggest speeding the video up which makes easier to understand the words! Excellent Video!
The intro is so goddamn good for late night studying
this channel is so help full. three days of studying and i didn't get anything until now. Thank you so much
this is so damn helpful. i have a test tomorrow and i was so confused but this really helped! thank you so much!
i hate physics so much but this helped alot thank you!
why do you hate physics, it's so interesting!
@@MrKK-gn5ml yeah im just so bad at it ahah
i have a test tomorrow and this has really helped me! Thanks! 😊
THESE VIDEOS GIVE ME CHILLS
I have practice mocks tomorrow in prep for my November ones and your videos are helping me so much! I'm hoping to get a 5/4-5/5 at GCSE :))
Glad you like them - we also have a website now: www.cognitoedu.org
how did it go?
@@awab1605 good!! I got a 5/5
@@Belledoesblogs That’s poor mate it’s combined aswell shocking
@@ВладаРепубликеСрбије I was foundation lol
I am facinated by light, congratulations. You have earned a sub by me.
I thank u so much u dont understand how much u have helped me
so much better than any other vids I've watched
Best channel. Get off rubbish schools and watch this instead
These science videos are the only reasons I’ve passed my GCSEs 🫶
This is the best channel for chemistry biology and physics 🔥🔥🔥
I learn more from a 5min video than 1hour lessons thank you so much for simplifying everything
Thanks for your help.
Such a helpful video 👍👍👍👍👍👍👍👍
Enjoyed...😍 love it keep up the good work
My physics exam is in 3 hours. And I am here 😂❤
Could you maybe also create a video explaining how to calculate the refracted angle? because for my school that is needed, I don't understand how to calculate the angle because the teacher doesn't explain well especially during online classes
You have no idea how much time these saved tysm
thank you very much i have my final exam tomorrow and didn't understand a word from my teacher but I now understand it very well thank you so much
Glad it helped!
Very clear and helpful, thank you💯
It is one of the Best channels for science subjects
Thanks Vishaal, we appreciate it 👍
Thanks a ton. I was able to get a good score in my test thanks to this topic. THANKKKKKKKYOUUUU
Most welcome 😊
I cannot put into words how useful this is to me. You made an incredibly good explanation, and you make incredibly good videos, so I subscribed.
Ah thanks DigitalGamerIII glad the video was useful!! 👍
4 years later you still explain more than my teacher
An absolute life saver, HUGE THANKS🙏🏻
Plz plz upload as many videos as u can... Because they are lifesaver weapon to keep the edu alive in these hard days of coroooonaaaaa....
Wow, very helpful, thanks!!!!
ur videos are very helpful
Sir i was afraid of waves as i was sick during the teacher taught waves and i was absent and when i looked at the book it was just diagram and they didn't teach step by step but afte watching this video all my doubts are cleared so thank you sir(i am an igcse student btw )
I owe you alot! You are really helping me through my boards. Thankyou so much man
Great video, (except your prism diagram is incorrect).
My physics exam is in 7 hours this really helps
How'd go buddy?
I have mine tomorrow
Thank you so much. Was preparing for my singaporean o levels this really helped
thank u so muchhhh i was just studying for my physics subj and this defintely helped by alot.
this was so helpful
I THANK YOU SOOOO MUCH, this helped me sooo much, YOUR LIKE LITTERLY THE BEST
No problem 😊
@@Cognitoedu is black light a thing and what happens if it goes through a prism
omg I never understood my teacher explain this topic, thank u so much✌️
Mere sir parha parha ke ye topic par kabhi bhi mujhe samajh nahi ai but cognito is legend❤
idk what i would do with out this guy
There is a mistake in the video description, where it says that wavelength stays the same during refraction. The video itself has the correct physics though -- frequency is unchanged, wavelength changes proportionally to the speed.
At 4:53, the spectrum exits the triangular prism incorrectly. It should refract downwards, further way from the normal.
na
No jokenot even doing my GSCE's But this helps for my PHYSICS exams lots
Thank you so much 😊 for helping me for exams your videos helped me a lot :))
Excellent videos, but on this one the dispersion diagram towards the end is incorrect as the emergent rays refract back towards the normal rather than away. An important detail, as at IGCSE the examiners look for students to sketch and/or describe this pattern of refraction.
thank you cognito i appreciate it boss
Best explanation ever
love these vids there is nothing that comes event close in terms of quality on youtube to your vids
Very much helpful
Thank you so much. You made it so much clearer!! Thank youuu
Glad it helped!
Thank you so much ❤This helped me a lot !!
Dis helps me a lot thankz
So helpfull
please continue your content
its so helpful!
thank you sooooooooooooooo much. It was very very very helpful
thanks Aimen glad you enjoyed it
tysm this rlly helps i have my mocks in 2 days ty this is literally so helpful the teachers were so confusion and nobody understands her ur a lifesaver
Hi! Great video, i just have one question. If something bends towards the normal, does that mean that it has a lower wavelength?
Yes the wavelength is shorter as for the wave to bend towards the normal it will be getting slower and frequency does not change
@@TheVkky ok thank you!!
Your triangular prism at 4:58 is INCORRECT >:(
Huh?
Tru
at 4:20 you said that the frequency always stays the same and it's always the wavelength that changes but i thought that the frequency and wavelength always relate. if you have a small wavelength the frequency will be higher than a wave with a higher wavelength?
What I know is that what you said works for sound waves. Don't know about light waves though
You guys are amazing. Keep up the good work
Thank you! Will do!
So the Refracted ray's angle is always half angle of incidence?
no he said to halve it because that's probably a level stuff or even higher so he said just to halve it
If you’d like to practise what's covered in this video, check out the lesson on the Cognito platform - cognitoedu.org/coursesubtopic/p2-gcse-aqa-h-t_4.04. The platform’s totally free, and has been built to make learning and revision as easy as possible. The main features are:
- Lessons organised by topic, only the lessons relevant to your specific exam board and tier are shown.
- Automatic progress tracking. Progress bars tell you what you’re doing well at, and what you need to spend some time on.
- Practise quizzes so you can test your knowledge. You can quiz yourself on any combination of topics you like.
- A huge number of fully-hinted questions that take you step-by-step through some of the trickiest calculations & concepts.
- A comprehensive bank of past exam papers, organised both by year, and also by topic.
Amadeus & Tom
do you have it on a app?
if speed increases, wave length decreases right?
There is no change of media, yet waves in a Ripple Tank are refracted (at a boundary between deep /shallow water). How can this be explained?
man takes 5 minutes while my teacher took 3 days to barely finish this shit
This was so helpful thnk you sm! Keep it up 😁
Can someone explain to me 0:48 where it said "the higher the density, the slower the wave"
I heard somewhere that the higher the density, the faster the wave travel since the particles would be more closely packed together, therefore it would be easier to reach by the wave
Good question. For sound waves, the denser the medium, the faster the speed of travel, but here, it's about light rays.
tyyyy rly helpful
you make it make sense
Hello, if the incident ray of white light entering a prism is combined (white), and the colours split apart by refraction causing various angles due to wavespeed within the prism, how come the emergent ray is not converted back into white light when entering back into the air? As the density is as it was originally. Thanks.
You see, what you describe would be happening inside a glass cuboid, for example. When both boundaries are parallel, one would split the wavelengths, and the second would merge the wavelengths - again giving white light. Remember this: the normals in a cuboid are parallel. Since in a triangular prism the boundaries are not parallel, the normals are not parallel. When first entering the glass, the rays are refracted and thrown apart within the glass prism. On the second side of the prism, the angle of the normal changes. The normal is perpendicular to the boundary. When moving from a dense to a less dense medium, the wave speed increases and the ray bends away from the normal. Because of the different wavelengths, on the second side the split rays are bent to different degrees a second time, further distancing them apart. This is best understood with a correct diagram. I appreciate my wording may be slightly rushed but I hope it helps you to understand!
@@groggers Wow
@@groggers thanks
Make one for the refractive index and critical angle
quarantine homework
Elnaby YESSS Sir
ISLA HOWARD LOVES THESE VIDEOS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Why was refractive index not covered in this video?
1:34 giggly hawk tuah!
Thank you SO MUCH😭😭😭🙏🙏🙏🙏
why does frequency never change yet wavelength changes if both are inversely proportional
Amazing video!
wait but how come when the ray enters a more dense medium it supposedly refracts towards it when in the diagram it looks like it bended away from it?
in a more dense material, the light moves towards the normal, and the diagram does show this
may i know why during refraction the frequency will remain unchanged🧐~?
I’m in year 7 and yet my science teacher sent me this 😂
Bits and Bobs with Hattie!! ! Damn that’s crazy bro
Stfu
Ewan Harrison 😂
Yo
lmao guys-
thank you so much
God Bless you 🤍🤍
3:51 incidence and emergent ray need to be parallel?
Hiya - Yes exactly - if the 2 sides of the object are parallel (e.g. 2 sides of the rectangle), then the incident and emergent ray should be parallel.
Ok thanks
GREAT VIDEO
thanks so much!👍
Jesus loves u repent and believe in the GOSPEL he died to forgive ALL your sins and give u eternal life accept him before its too late JUDGMENT DAY IS COMING
You explained much better than fucking learncoach.... omg thank you
Correction. The first point is correct.