Physics can seem overwhelming, but understanding waves, energy, and motion... Show more
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Updated Mar 27, 2026
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Comprehensive GCSE Physics Revision Notes
Matilda Gant
@atildaant_rvlgyqbimq
1 / 4
Waves and the Electromagnetic Spectrum
Ever wondered how your Wi-Fi signal reaches your laptop or how X-rays can see through your skin? It's all about waves - energy carriers that are everywhere around you.
Waves come in two main types: transverse (like light waves that wiggle up and down) and longitudinal (like sound waves that push and pull through air). The key measurements you need to know are wavelength (distance between wave peaks), amplitude (how big the wave is), and frequency (how many waves pass per second).
The electromagnetic spectrum is basically nature's energy menu, from radio waves to gamma rays. Radio waves handle communication, microwaves cook your food and power satellites, infrared gives you heat, visible light lets you see, UV rays tan your skin, X-rays image bones, and gamma rays fight cancer. Most of these are safe (non-ionising), but X-rays and gamma rays pack enough punch to be ionising.
Quick tip: Remember the wave equation v = f × λ - it works for all waves and is dead useful for calculations!
Energy Stores and Transfers
Your body, a stretched rubber band, and a nuclear power station all have one thing in common - they're energy storage systems waiting to transfer their power to something else.
Energy stores are like different types of batteries in the world around you. Kinetic energy powers moving objects, gravitational potential energy exists in anything with height, elastic potential energy sits in stretched or squashed things, and thermal energy relates to temperature. Chemical, nuclear, magnetic, and electrostatic energy complete the set.
Energy always follows one golden rule: it can't be created or destroyed, only transferred between stores. However, not all transfers are useful - dissipated energy gets wasted as heat through friction. That's where efficiency comes in, calculated as useful output divided by total input.
Thermal insulation in buildings works by using materials with low conductivity to reduce heat transfer rates. The thicker your walls and the better your insulators, the less energy (and money) you'll waste heating your home.
Remember: All energy eventually ends up as heat in the surroundings - that's why machines get warm when they work!
Velocity-Time Graphs
Reading a velocity-time graph is like reading the story of how something moves - and once you crack the code, you'll never struggle with motion problems again.
The shape of the line tells you everything. A horizontal line means constant velocity (steady speed in one direction), with higher lines showing faster speeds. A sloped line reveals acceleration - the steeper the slope, the greater the acceleration. If the line slopes downward, the object is slowing down.
Here's the clever bit: the gradient of the line gives you the acceleration value, whilst the area under the line shows the total distance travelled. This means you can extract loads of information just by looking at the graph's shape.
Pro tip: If the line crosses the time axis (goes negative), the object has changed direction - it's now moving backwards!
Distance-Time Graphs
Distance-time graphs show a completely different story about motion, focusing on position rather than speed - think of them as tracking where something is rather than how fast it's going.
A horizontal line on a distance-time graph means the object is stationary (not moving at all). A straight sloped line shows constant speed - gentle slopes mean slow movement, whilst steep slopes indicate rapid motion. Curved lines reveal changing speed, with the curve getting steeper for acceleration.
The key difference from velocity-time graphs is that the gradient here shows speed, not acceleration. A steeper gradient always means faster movement, regardless of whether the line curves or stays straight.
These graphs are brilliant for tracking journeys and comparing speeds between different objects or time periods.
Quick check: If you can find the gradient, you can find the speed - it's just the change in distance divided by the change in time!
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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 Knowunity AI. 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 Knowunity AI. 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
Comprehensive GCSE Physics Revision Notes
Matilda Gant
@atildaant_rvlgyqbimq
Physics can seem overwhelming, but understanding waves, energy, and motion graphs is actually quite straightforward once you break it down. These fundamental concepts explain everything from how your mobile phone works to why insulation keeps your home warm and how... Show more
Waves and the Electromagnetic Spectrum
Ever wondered how your Wi-Fi signal reaches your laptop or how X-rays can see through your skin? It's all about waves - energy carriers that are everywhere around you.
Waves come in two main types: transverse (like light waves that wiggle up and down) and longitudinal (like sound waves that push and pull through air). The key measurements you need to know are wavelength (distance between wave peaks), amplitude (how big the wave is), and frequency (how many waves pass per second).
The electromagnetic spectrum is basically nature's energy menu, from radio waves to gamma rays. Radio waves handle communication, microwaves cook your food and power satellites, infrared gives you heat, visible light lets you see, UV rays tan your skin, X-rays image bones, and gamma rays fight cancer. Most of these are safe (non-ionising), but X-rays and gamma rays pack enough punch to be ionising.
Quick tip: Remember the wave equation v = f × λ - it works for all waves and is dead useful for calculations!
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Energy Stores and Transfers
Your body, a stretched rubber band, and a nuclear power station all have one thing in common - they're energy storage systems waiting to transfer their power to something else.
Energy stores are like different types of batteries in the world around you. Kinetic energy powers moving objects, gravitational potential energy exists in anything with height, elastic potential energy sits in stretched or squashed things, and thermal energy relates to temperature. Chemical, nuclear, magnetic, and electrostatic energy complete the set.
Energy always follows one golden rule: it can't be created or destroyed, only transferred between stores. However, not all transfers are useful - dissipated energy gets wasted as heat through friction. That's where efficiency comes in, calculated as useful output divided by total input.
Thermal insulation in buildings works by using materials with low conductivity to reduce heat transfer rates. The thicker your walls and the better your insulators, the less energy (and money) you'll waste heating your home.
Remember: All energy eventually ends up as heat in the surroundings - that's why machines get warm when they work!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Velocity-Time Graphs
Reading a velocity-time graph is like reading the story of how something moves - and once you crack the code, you'll never struggle with motion problems again.
The shape of the line tells you everything. A horizontal line means constant velocity (steady speed in one direction), with higher lines showing faster speeds. A sloped line reveals acceleration - the steeper the slope, the greater the acceleration. If the line slopes downward, the object is slowing down.
Here's the clever bit: the gradient of the line gives you the acceleration value, whilst the area under the line shows the total distance travelled. This means you can extract loads of information just by looking at the graph's shape.
Pro tip: If the line crosses the time axis (goes negative), the object has changed direction - it's now moving backwards!
Sign up to see the contentIt's free!
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Improve your grades
Join milions of students
Distance-Time Graphs
Distance-time graphs show a completely different story about motion, focusing on position rather than speed - think of them as tracking where something is rather than how fast it's going.
A horizontal line on a distance-time graph means the object is stationary (not moving at all). A straight sloped line shows constant speed - gentle slopes mean slow movement, whilst steep slopes indicate rapid motion. Curved lines reveal changing speed, with the curve getting steeper for acceleration.
The key difference from velocity-time graphs is that the gradient here shows speed, not acceleration. A steeper gradient always means faster movement, regardless of whether the line curves or stays straight.
These graphs are brilliant for tracking journeys and comparing speeds between different objects or time periods.
Quick check: If you can find the gradient, you can find the speed - it's just the change in distance divided by the change in time!
We thought you’d never ask...
What is the Knowunity AI companion?
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.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
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Students love us — and so will you.
4.6/5
App Store
4.7/5
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 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 Knowunity AI. 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 Knowunity AI. 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