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!
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!
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!
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
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.
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
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
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.
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!
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
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.
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@@olliemellor1171 they both are
And maths :)
@@olliemellor1171 oof controversial
@@Cognitoedu Lmfao
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
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
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
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!
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 💛
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
Guys, I suggest speeding the video up which makes easier to understand the words! Excellent Video!
this is so damn helpful. i have a test tomorrow and i was so confused but this really helped! thank you so much!
i loove this channel sm, its literally saving my grades at this point. i love the aesthetic, too......
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
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 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?
Thanks for your help.
Such a helpful video 👍👍👍👍👍👍👍👍
i have a test tomorrow and this has really helped me! Thanks! 😊
I thank u so much u dont understand how much u have helped me
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.
I am facinated by light, congratulations. You have earned a sub by me.
These science videos are the only reasons I’ve passed my GCSEs 🫶
THESE VIDEOS GIVE ME CHILLS
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
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
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 learn more from a 5min video than 1hour lessons thank you so much for simplifying everything
so much better than any other vids I've watched
Dis helps me a lot thankz
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
Enjoyed...😍 love it keep up the good work
Great video, (except your prism diagram is incorrect).
This is the best channel for chemistry biology and physics 🔥🔥🔥
I owe you alot! You are really helping me through my boards. Thankyou so much man
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!! 👍
Very clear and helpful, thank you💯
this was so helpful
4 years later you still explain more than my teacher
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!
An absolute life saver, HUGE THANKS🙏🏻
thank u so muchhhh i was just studying for my physics subj and this defintely helped by alot.
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 so much. Was preparing for my singaporean o levels this really helped
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....
if speed increases, wave length decreases right?
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
Wow, very helpful, thanks!!!!
My physics exam is in 7 hours this really helps
How'd go buddy?
I have mine tomorrow
omg I never understood my teacher explain this topic, thank u so much✌️
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
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
No jokenot even doing my GSCE's But this helps for my PHYSICS exams lots
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
Thank you so much. You made it so much clearer!! Thank youuu
Glad it helped!
It is one of the Best channels for science subjects
Thanks Vishaal, we appreciate it 👍
Very much helpful
ur videos are very helpful
why does frequency never change yet wavelength changes if both are inversely proportional
At 4:53, the spectrum exits the triangular prism incorrectly. It should refract downwards, further way from the normal.
na
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?
Thank you so much ❤This helped me a lot !!
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
tyyyy rly helpful
man takes 5 minutes while my teacher took 3 days to barely finish this shit
So helpfull
please continue your content
its so helpful!
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.
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.
You explained much better than fucking learncoach.... omg thank you
This was so helpful thnk you sm! Keep it up 😁
may i know why during refraction the frequency will remain unchanged🧐~?
idk what i would do with out this guy
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!!
You guys are amazing. Keep up the good work
Thank you! Will do!
you make it make sense
Best explanation ever
Make one for the refractive index and critical angle
thank you sooooooooooooooo much. It was very very very helpful
thanks Aimen glad you enjoyed it
1:34 giggly hawk tuah!
Amazing video!
Thank you so much
mr K class?
Thank you SO MUCH😭😭😭🙏🙏🙏🙏
Hi, great vieos, helijng me understand a lot. Have any videos on snells law?
God Bless you 🤍🤍
My physics exam is in 3 hours. And I am here 😂❤
thanks so much!👍
GREAT VIDEO
quarantine homework
Elnaby YESSS Sir
Done sucribing
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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-
can u teach my teacher how to explain this to us, cuz she doesnt even uderstands it !!
wonderful
Physics gang 🥶🥶🥶🥶
4:55
honestly saved my life ahaha ty!!!
when it’s slower it goes towards the normal
ertgrul
Relatable