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1l the quest for political stability: germany, 1871-1991
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2d religious conflict and the church in england, c1529-c1570
2o democracy and nazism: germany, 1918-1945
1f industrialisation and the people: britain, c1783-1885
1c the tudors: england, 1485-1603
2m wars and welfare: britain in transition, 1906-1957
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2s the making of modern britain, 1951-2007
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Physics
28 Nov 2025
565
2 pages
Subhan ๐จโ๐ฌ @soobbb
This physics unit covers two crucial areas: waves and optics, plus electromagnetic wave applications. You'll master everything from... Show more
Ever wondered how your internet travels through cables at lightning speed? Fibre optic cables use total internal reflection to transmit data using light waves. When light hits the boundary between two materials at an angle greater than the critical angle, it reflects completely back instead of passing through.
The refractive index tells you how much light slows down in a material compared to air. Using the formula n = sin ฮธc (where ฮธc is the critical angle), you can calculate that a material with a critical angle of 43.8ยฐ has a refractive index of approximately 1.45. Light travels slower in denser materials - if the refractive index is 1.48, light speed becomes 3ร10โธ รท 1.48 = 2.03ร10โธ m/s.
Fibre optic cables have three main layers the core (carries light), cladding (reflects light back), and protective outer jacket. Multimode fibres allow multiple light paths, whilst single mode fibres use just one path for clearer signals over longer distances.
Key Tip Remember N=CV means refractive index equals speed of light in vacuum divided by speed of light in the material.
Modern communication relies on electromagnetic waves - satellites use microwaves, mobile phones use radio waves, and infrared controls your TV remote. The inverse square law shows that wave intensity decreases rapidly with distance, which is why your phone signal gets weaker further from towers.
Waves are everywhere - from the music you hear to earthquakes shaking the ground. An oscillation is simply something moving back and forth repeatedly, creating waves that transfer energy without moving matter.
Transverse waves (like light) vibrate perpendicular to their direction of travel, whilst longitudinal waves (like sound) vibrate parallel to their direction. You can calculate wave speed using v = fฮป (frequency ร wavelength). Sound waves create compressions (particles pushed together) and rarefactions (particles spread apart) as they travel.
Diffraction happens when waves bend around obstacles - it's why you can hear someone calling from around a corner. When waves reflect and interfere with themselves, they create stationary waves with fixed nodes (no movement) and antinodes (maximum movement). This resonance effect is crucial for musical instruments - guitars and violins use string resonance, whilst wind instruments use air column resonance.
Remember Frequency is measured in hertz (Hz), and displacement means how far something moves from its rest position.
Diffraction gratings split white light into its component colours, creating emission spectra that scientists use to identify chemical elements - each element produces a unique light fingerprint. This technique helps astronomers determine what distant stars are made of, proving that waves aren't just physics theory but powerful analytical tools.
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help โ all at your fingertips.
10
Smart Tools NEW
Transform this note into: โ 50+ Practice Questions โ Interactive Flashcards โ Full Mock Exam โ Essay Outlines
Explore essential key concepts related to waves in physics, including wave types, properties, and behaviors. This summary covers transverse and longitudinal waves, the electromagnetic spectrum, and wave interactions such as reflection, refraction, and absorption. Ideal for A-level physics students preparing for exams.
PhysicsExplore key concepts in wave behavior, including standing waves, phase difference, and wave properties. This summary covers essential topics such as constructive and destructive interference, refraction, and diffraction, providing a comprehensive overview for A Level Physics students. Ideal for exam preparation and understanding wave dynamics.
PhysicsBTEC applied science unit 1 waves, physics
PhysicsApp Store
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because itโs too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didnโt even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโm sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH ๐๐๐ฒ๐ค๐โจ๐๐ฎ
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because itโs too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didnโt even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโm sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH ๐๐๐ฒ๐ค๐โจ๐๐ฎ
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Subhan ๐จโ๐ฌ
@soobbb
This physics unit covers two crucial areas: waves and optics, plus electromagnetic wave applications. You'll master everything from basic wave properties to how fibre optic cables work in your internet connection.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Ever wondered how your internet travels through cables at lightning speed? Fibre optic cables use total internal reflection to transmit data using light waves. When light hits the boundary between two materials at an angle greater than the critical angle, it reflects completely back instead of passing through.
The refractive index tells you how much light slows down in a material compared to air. Using the formula n = sin ฮธc (where ฮธc is the critical angle), you can calculate that a material with a critical angle of 43.8ยฐ has a refractive index of approximately 1.45. Light travels slower in denser materials - if the refractive index is 1.48, light speed becomes 3ร10โธ รท 1.48 = 2.03ร10โธ m/s.
Fibre optic cables have three main layers: the core (carries light), cladding (reflects light back), and protective outer jacket. Multimode fibres allow multiple light paths, whilst single mode fibres use just one path for clearer signals over longer distances.
Key Tip: Remember N=CV means refractive index equals speed of light in vacuum divided by speed of light in the material.
Modern communication relies on electromagnetic waves - satellites use microwaves, mobile phones use radio waves, and infrared controls your TV remote. The inverse square law shows that wave intensity decreases rapidly with distance, which is why your phone signal gets weaker further from towers.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Waves are everywhere - from the music you hear to earthquakes shaking the ground. An oscillation is simply something moving back and forth repeatedly, creating waves that transfer energy without moving matter.
Transverse waves (like light) vibrate perpendicular to their direction of travel, whilst longitudinal waves (like sound) vibrate parallel to their direction. You can calculate wave speed using v = fฮป (frequency ร wavelength). Sound waves create compressions (particles pushed together) and rarefactions (particles spread apart) as they travel.
Diffraction happens when waves bend around obstacles - it's why you can hear someone calling from around a corner. When waves reflect and interfere with themselves, they create stationary waves with fixed nodes (no movement) and antinodes (maximum movement). This resonance effect is crucial for musical instruments - guitars and violins use string resonance, whilst wind instruments use air column resonance.
Remember: Frequency is measured in hertz (Hz), and displacement means how far something moves from its rest position.
Diffraction gratings split white light into its component colours, creating emission spectra that scientists use to identify chemical elements - each element produces a unique light fingerprint. This technique helps astronomers determine what distant stars are made of, proving that waves aren't just physics theory but powerful analytical tools.
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help โ all at your fingertips.
10
Smart Tools NEW
Transform this note into: โ 50+ Practice Questions โ Interactive Flashcards โ Full Mock Exam โ Essay Outlines
Explore essential key concepts related to waves in physics, including wave types, properties, and behaviors. This summary covers transverse and longitudinal waves, the electromagnetic spectrum, and wave interactions such as reflection, refraction, and absorption. Ideal for A-level physics students preparing for exams.
PhysicsExplore key concepts in wave behavior, including standing waves, phase difference, and wave properties. This summary covers essential topics such as constructive and destructive interference, refraction, and diffraction, providing a comprehensive overview for A Level Physics students. Ideal for exam preparation and understanding wave dynamics.
PhysicsBTEC applied science unit 1 waves, physics
PhysicsApp Store
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because itโs too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didnโt even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโm sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH ๐๐๐ฒ๐ค๐โจ๐๐ฎ
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because itโs too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didnโt even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as Iโm sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH ๐๐๐ฒ๐ค๐โจ๐๐ฎ
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
