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Patryk Wielgus
06/12/2025
Physics
Physics P1 – Conservation and Dissipation of Energy .
226
•
6 Dec 2025
•
Physics P1: Energy Conservation and Dissipation Simplified Notes
Patryk Wielgus
@patryk_wielgus
1 / 3
Energy Stores and Conservation
Ever wondered what happens to the energy when a football hits the goalpost? The ball's kinetic energy doesn't just vanish - it gets transferred to sound energy (that satisfying thud!) and a bit of heat.
Energy conservation is actually quite simple: energy can't be created or destroyed, only moved around. Think of it like money - you can spend it on different things, but the total amount stays the same. When systems change, the energy just shifts between different stores.
There are nine main energy stores you need to know. The handy mnemonic "Host Kids Hate Learning GCSE Energy Names" covers them all: Magnetic, Kinetic, Heat (thermal), gravitational potential, Chemical, Sound, Elastic, Electric, and Nuclear.
Quick Tip: Kinetic energy (moving objects) uses the formula Ek = 0.5 × mass × speed², whilst gravitational potential energy (objects at height) uses Ep = mgh.
How Energy Moves and Work Gets Done
When you're swinging on a playground swing, you're watching energy conservation in action. At the top of your swing, you've got maximum gravitational potential energy. As you swing down, this converts to kinetic energy, with some heat dissipating to the surroundings through friction.
A closed system means no energy escapes to the outside world - though energy can still move between different stores within the system. Real-world examples are rare since energy usually leaks out somehow.
Work done happens when a force makes something move. The equation is simple: Work done = force × distance. If nothing moves, no work gets done - even if you're pushing against a brick wall with all your strength.
Remember: When you overcome friction, that work gets transferred as thermal energy to the objects rubbing together and the surroundings.
Energy Efficiency and Electrical Appliances
Not all energy does what we want it to do. Useful energy ends up where we need it (like heat from your radiator), whilst wasted energy goes elsewhere (like the heat your phone produces when charging). Both types eventually warm up the surroundings.
Efficiency tells us how good a machine is at avoiding waste. The formula is: Efficiency = (useful energy output ÷ total energy input) × 100. No machine can be more than 100% efficient - that would break the laws of physics!
Most energy waste comes from friction, air resistance, and electrical resistance. You can boost efficiency by reducing these factors or finding ways to recycle the waste energy.
Power measures how quickly appliances transfer energy, measured in watts. Remember: Power = energy ÷ time. Your kettle has high power because it transfers lots of energy quickly, whilst your phone charger has lower power.
Exam Tip: Efficiency can be written as a decimal (0.25) or percentage (25%) - both mean the same thing.
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Basil
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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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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!
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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
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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
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
Physics P1: Energy Conservation and Dissipation Simplified Notes
Patryk Wielgus
@patryk_wielgus
Energy is all around us, constantly changing forms but never disappearing completely. Understanding how energy moves between different stores and why machines aren't perfectly efficient will help you ace your physics exams and make sense of the world around you.
Energy Stores and Conservation
Ever wondered what happens to the energy when a football hits the goalpost? The ball's kinetic energy doesn't just vanish - it gets transferred to sound energy (that satisfying thud!) and a bit of heat.
Energy conservation is actually quite simple: energy can't be created or destroyed, only moved around. Think of it like money - you can spend it on different things, but the total amount stays the same. When systems change, the energy just shifts between different stores.
There are nine main energy stores you need to know. The handy mnemonic "Host Kids Hate Learning GCSE Energy Names" covers them all: Magnetic, Kinetic, Heat (thermal), gravitational potential, Chemical, Sound, Elastic, Electric, and Nuclear.
Quick Tip: Kinetic energy (moving objects) uses the formula Ek = 0.5 × mass × speed², whilst gravitational potential energy (objects at height) uses Ep = mgh.
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How Energy Moves and Work Gets Done
When you're swinging on a playground swing, you're watching energy conservation in action. At the top of your swing, you've got maximum gravitational potential energy. As you swing down, this converts to kinetic energy, with some heat dissipating to the surroundings through friction.
A closed system means no energy escapes to the outside world - though energy can still move between different stores within the system. Real-world examples are rare since energy usually leaks out somehow.
Work done happens when a force makes something move. The equation is simple: Work done = force × distance. If nothing moves, no work gets done - even if you're pushing against a brick wall with all your strength.
Remember: When you overcome friction, that work gets transferred as thermal energy to the objects rubbing together and the surroundings.
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Energy Efficiency and Electrical Appliances
Not all energy does what we want it to do. Useful energy ends up where we need it (like heat from your radiator), whilst wasted energy goes elsewhere (like the heat your phone produces when charging). Both types eventually warm up the surroundings.
Efficiency tells us how good a machine is at avoiding waste. The formula is: Efficiency = (useful energy output ÷ total energy input) × 100. No machine can be more than 100% efficient - that would break the laws of physics!
Most energy waste comes from friction, air resistance, and electrical resistance. You can boost efficiency by reducing these factors or finding ways to recycle the waste energy.
Power measures how quickly appliances transfer energy, measured in watts. Remember: Power = energy ÷ time. Your kettle has high power because it transfers lots of energy quickly, whilst your phone charger has lower power.
Exam Tip: Efficiency can be written as a decimal (0.25) or percentage (25%) - both mean the same thing.
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?
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Is Knowunity really free of charge?
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Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.9/5
App Store
4.8/5
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 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