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Reflection of Light
Ever wondered why you can see yourself perfectly in a bathroom mirror but only catch blurry glimpses in a puddle? It's all about how light waves bounce off different surfaces.
When light hits a flat surface like a mirror, it follows a simple rule: the angle of reflection equals the angle of incidence. Think of it like bouncing a ball off a wall - throw it at an angle, and it bounces back at the same angle. The normal is an imaginary line perpendicular to the surface that helps us measure these angles.
Specular reflection happens with smooth surfaces like mirrors, where all the light rays bounce off in the same direction, creating clear images. Diffuse reflection occurs with rough surfaces like paper, scattering light in all directions - which is why you can't see your reflection in a textbook!
Key Point: Virtual images (like your reflection) appear to be behind the mirror but can't be projected onto a screen, unlike real images that actually focus light rays.
Refraction of Light
You've probably noticed how a straw looks bent in a glass of water - that's refraction in action, and it happens because light travels at different speeds through different materials.
When light moves from air into glass (or water), it slows down and bends towards the normal. When it goes from glass back to air, it speeds up and bends away from the normal. This happens because glass is optically more dense than air.
The key rule is simple: light bends towards the normal when entering a denser medium, and away from the normal when entering a less dense medium. This bending creates optical illusions and makes objects appear in different positions than they actually are.
Remember: The amount of bending depends on how much the light's speed changes between the two materials.
Light and Colour
White light isn't actually white - it's every colour mixed together! When you see a red apple or blue sky, you're seeing how different materials interact with the full spectrum of light wavelengths.
Colour filters work by absorbing certain wavelengths and letting others pass through. The primary colours of light are red, green, and blue, which can combine to create any other colour. Objects appear coloured because their pigments absorb some wavelengths and reflect others back to your eyes.
Transparent objects let all light pass through clearly, translucent objects let light through but scatter it (like frosted glass), and opaque objects block light completely. A white surface reflects all colours equally, while a black surface absorbs them all.
Fun Fact: You see objects as certain colours because they're actually rejecting those wavelengths - a red apple absorbs all colours except red!
Lenses and Image Formation
Lenses are curved pieces of glass that bend light to create images, and they're everywhere - in your eyes, cameras, microscopes, and glasses.
Convex lenses (thicker in the middle) make parallel light rays converge to a focus point. They can create both real images (that appear on screens) and virtual images (magnified views like through a magnifying glass). Concave lenses (thinner in the middle) make light rays diverge and are used to correct short-sightedness.
Magnification is calculated as image height divided by object height. If the result is greater than 1, the image is bigger than the object. The position and size of the image depends on how far the object is from the lens compared to the focal length.
Cameras use convex lenses to focus real images onto film or digital sensors. For distant objects, the lens needs to be exactly one focal length from the film, but for closer objects, you need to move the lens further away.
Quick Tip: Draw ray diagrams using two simple rules - one ray goes parallel to the axis then through the focus, another goes straight through the lens centre.
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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.
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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 didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
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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 😍😁😲🤑💗✨🎀😮
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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
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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 it’s 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
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Sudenaz Ocak
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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 didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m 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 😍😁😲🤑💗✨🎀😮
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
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GCSE Physics AQA - Chapter P14: Light Notes
Light behaves as waves that can bounce off surfaces, bend when passing through materials, and create the colours we see around us. Understanding how light reflects, refracts, and interacts with lenses helps explain everything from why we see our reflection... Show more
Reflection of Light
Ever wondered why you can see yourself perfectly in a bathroom mirror but only catch blurry glimpses in a puddle? It's all about how light waves bounce off different surfaces.
When light hits a flat surface like a mirror, it follows a simple rule: the angle of reflection equals the angle of incidence. Think of it like bouncing a ball off a wall - throw it at an angle, and it bounces back at the same angle. The normal is an imaginary line perpendicular to the surface that helps us measure these angles.
Specular reflection happens with smooth surfaces like mirrors, where all the light rays bounce off in the same direction, creating clear images. Diffuse reflection occurs with rough surfaces like paper, scattering light in all directions - which is why you can't see your reflection in a textbook!
Key Point: Virtual images (like your reflection) appear to be behind the mirror but can't be projected onto a screen, unlike real images that actually focus light rays.
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Refraction of Light
You've probably noticed how a straw looks bent in a glass of water - that's refraction in action, and it happens because light travels at different speeds through different materials.
When light moves from air into glass (or water), it slows down and bends towards the normal. When it goes from glass back to air, it speeds up and bends away from the normal. This happens because glass is optically more dense than air.
The key rule is simple: light bends towards the normal when entering a denser medium, and away from the normal when entering a less dense medium. This bending creates optical illusions and makes objects appear in different positions than they actually are.
Remember: The amount of bending depends on how much the light's speed changes between the two materials.
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Light and Colour
White light isn't actually white - it's every colour mixed together! When you see a red apple or blue sky, you're seeing how different materials interact with the full spectrum of light wavelengths.
Colour filters work by absorbing certain wavelengths and letting others pass through. The primary colours of light are red, green, and blue, which can combine to create any other colour. Objects appear coloured because their pigments absorb some wavelengths and reflect others back to your eyes.
Transparent objects let all light pass through clearly, translucent objects let light through but scatter it (like frosted glass), and opaque objects block light completely. A white surface reflects all colours equally, while a black surface absorbs them all.
Fun Fact: You see objects as certain colours because they're actually rejecting those wavelengths - a red apple absorbs all colours except red!
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Lenses and Image Formation
Lenses are curved pieces of glass that bend light to create images, and they're everywhere - in your eyes, cameras, microscopes, and glasses.
Convex lenses (thicker in the middle) make parallel light rays converge to a focus point. They can create both real images (that appear on screens) and virtual images (magnified views like through a magnifying glass). Concave lenses (thinner in the middle) make light rays diverge and are used to correct short-sightedness.
Magnification is calculated as image height divided by object height. If the result is greater than 1, the image is bigger than the object. The position and size of the image depends on how far the object is from the lens compared to the focal length.
Cameras use convex lenses to focus real images onto film or digital sensors. For distant objects, the lens needs to be exactly one focal length from the film, but for closer objects, you need to move the lens further away.
Quick Tip: Draw ray diagrams using two simple rules - one ray goes parallel to the axis then through the focus, another goes straight through the lens centre.
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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 it’s 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 didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m 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 😍😁😲🤑💗✨🎀😮
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 it’s 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 didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m 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 😍😁😲🤑💗✨🎀😮
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