Maths
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Responding to change (a2 only)
Infection and response
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Organisms respond to changes in their internal and external environments (a-level only)
Biological molecules
Organisation
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Britain & the wider world: 1745 -1901
1l the quest for political stability: germany, 1871-1991
The cold war
Inter-war germany
Medieval period: 1066 -1509
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
World war two & the holocaust
2n revolution and dictatorship: russia, 1917-1953
2s the making of modern britain, 1951-2007
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Physics
10 Dec 2025
212
3 pages
Energy is everywhere around us - from the petrol in your car to the battery in your phone.... Show more
Work is basically what happens when a force makes something move. It's calculated as W = Fx (force times distance), but only when the force acts in the same direction as the movement.
When forces act at angles, things get slightly trickier. If a force acts at angle θ to the movement, you use W = Fxcos θ. Only the component of force in the direction of motion actually does work.
The conservation of energy principle is absolutely fundamental - energy never disappears, it just changes form. You'll need to master three key types gravitational potential energy , elastic potential energy , and kinetic energy .
Quick Tip Remember that energy always transforms from one type to another - it never vanishes into thin air!
Energy transformations happen constantly around you. When something falls, it loses gravitational potential energy and gains kinetic energy as it speeds up. Similarly, when a stretched spring is released, elastic potential energy converts to kinetic energy.
The work-energy relationship connects these concepts perfectly Fx = ½mv² - ½mu². This means the work done on an object equals its change in kinetic energy.
Let's see this in action if a 5kg block moving at 3m/s experiences a 12N force over 10m, you can calculate its final velocity. Substituting into the equation gives you 120 = 2.5v² - 22.5, so v = 7.5 m/s.
Power measures how quickly energy transfers occur, calculated as P = E/t. It's the rate of doing work or transferring energy.
Exam Tip The work-energy relationship is a favourite exam question - practice substituting values into Fx = ½mv² - ½mu²!
Dissipative forces like friction and drag are energy's biggest enemies - they reduce system efficiency by converting useful energy into heat. Think about car tyres heating up from friction or planes needing massive engines to overcome air resistance.
Engineers constantly battle these forces through clever design. Sports cars have pointed fronts to reduce drag, whilst athletes wear tight-fitting clothing to minimise air resistance during competitions.
Energy efficiency measures how much useful energy you get out compared to what you put in efficiency = (useful energy transfer ÷ total energy input) × 100. When calculating efficiency problems, remember that heat loss often equals the difference between potential and kinetic energy.
For frictional scenarios, you can find the frictional force using frictional force = ÷ distance. This relationship helps you quantify exactly how much energy dissipative forces waste.
Real-world Connection Understanding efficiency explains why electric cars are becoming popular - they waste far less energy than petrol engines!
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 – all at your fingertips.
5
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore key concepts in work, energy, and power through detailed questions and solutions. This resource covers elastic potential energy, Hooke's Law, the work-energy theorem, and more, providing a comprehensive understanding for students preparing for exams. Ideal for physics students seeking to master energy principles and their applications.
PhysicsExplore key concepts in Mechanics and Materials for AQA A-Level Physics, including Newton's Laws, energy conservation, kinematic equations, and projectile motion. This summary covers essential principles such as static equilibrium, elastic potential energy, and the work-energy principle, providing a comprehensive understanding for Year 12 and Year 13 students.
PhysicsExplore key concepts in Circular Motion and Simple Harmonic Motion (SHM) including centripetal force, acceleration, kinetic and potential energy, and equilibrium position. This summary provides essential formulas and principles for A Level Physics (AQA) students, focusing on the relationships between energy types and motion dynamics.
PhysicsExplore the key concepts of speed and velocity in physics, including average speed, instantaneous speed, and their applications. This summary covers essential formulas, measurement techniques, and real-world examples like speed cameras. Ideal for N5 Physics students seeking clarity on dynamics.
PhysicsExplore the principles of uniform circular motion, including tangential velocity, centripetal force, and acceleration. This summary covers key formulas, relationships, and experimental methods for understanding circular motion in A-level physics. Ideal for students preparing for exams.
PhysicsExplore detailed solutions to the OCR A Level Physics June 2018 paper, covering key concepts such as Newtonian Mechanics, Circular Motion, Gravitational Fields, and more. This comprehensive resource includes worked examples and explanations for each question, making it an essential study tool for mastering physics concepts and exam preparation.
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 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
Energy is everywhere around us - from the petrol in your car to the battery in your phone. Understanding how energy transfers and transforms is crucial for physics success and explains how everything in our world actually works.
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By signing up you accept Terms of Service and Privacy Policy
Work is basically what happens when a force makes something move. It's calculated as W = Fx (force times distance), but only when the force acts in the same direction as the movement.
When forces act at angles, things get slightly trickier. If a force acts at angle θ to the movement, you use W = Fxcos θ. Only the component of force in the direction of motion actually does work.
The conservation of energy principle is absolutely fundamental - energy never disappears, it just changes form. You'll need to master three key types: gravitational potential energy , elastic potential energy , and kinetic energy .
Quick Tip: Remember that energy always transforms from one type to another - it never vanishes into thin air!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Energy transformations happen constantly around you. When something falls, it loses gravitational potential energy and gains kinetic energy as it speeds up. Similarly, when a stretched spring is released, elastic potential energy converts to kinetic energy.
The work-energy relationship connects these concepts perfectly: Fx = ½mv² - ½mu². This means the work done on an object equals its change in kinetic energy.
Let's see this in action: if a 5kg block moving at 3m/s experiences a 12N force over 10m, you can calculate its final velocity. Substituting into the equation gives you 120 = 2.5v² - 22.5, so v = 7.5 m/s.
Power measures how quickly energy transfers occur, calculated as P = E/t. It's the rate of doing work or transferring energy.
Exam Tip: The work-energy relationship is a favourite exam question - practice substituting values into Fx = ½mv² - ½mu²!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Dissipative forces like friction and drag are energy's biggest enemies - they reduce system efficiency by converting useful energy into heat. Think about car tyres heating up from friction or planes needing massive engines to overcome air resistance.
Engineers constantly battle these forces through clever design. Sports cars have pointed fronts to reduce drag, whilst athletes wear tight-fitting clothing to minimise air resistance during competitions.
Energy efficiency measures how much useful energy you get out compared to what you put in: efficiency = (useful energy transfer ÷ total energy input) × 100. When calculating efficiency problems, remember that heat loss often equals the difference between potential and kinetic energy.
For frictional scenarios, you can find the frictional force using: frictional force = ÷ distance. This relationship helps you quantify exactly how much energy dissipative forces waste.
Real-world Connection: Understanding efficiency explains why electric cars are becoming popular - they waste far less energy than petrol engines!
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 – all at your fingertips.
5
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore key concepts in work, energy, and power through detailed questions and solutions. This resource covers elastic potential energy, Hooke's Law, the work-energy theorem, and more, providing a comprehensive understanding for students preparing for exams. Ideal for physics students seeking to master energy principles and their applications.
PhysicsExplore key concepts in Mechanics and Materials for AQA A-Level Physics, including Newton's Laws, energy conservation, kinematic equations, and projectile motion. This summary covers essential principles such as static equilibrium, elastic potential energy, and the work-energy principle, providing a comprehensive understanding for Year 12 and Year 13 students.
PhysicsExplore key concepts in Circular Motion and Simple Harmonic Motion (SHM) including centripetal force, acceleration, kinetic and potential energy, and equilibrium position. This summary provides essential formulas and principles for A Level Physics (AQA) students, focusing on the relationships between energy types and motion dynamics.
PhysicsExplore the key concepts of speed and velocity in physics, including average speed, instantaneous speed, and their applications. This summary covers essential formulas, measurement techniques, and real-world examples like speed cameras. Ideal for N5 Physics students seeking clarity on dynamics.
PhysicsExplore the principles of uniform circular motion, including tangential velocity, centripetal force, and acceleration. This summary covers key formulas, relationships, and experimental methods for understanding circular motion in A-level physics. Ideal for students preparing for exams.
PhysicsExplore detailed solutions to the OCR A Level Physics June 2018 paper, covering key concepts such as Newtonian Mechanics, Circular Motion, Gravitational Fields, and more. This comprehensive resource includes worked examples and explanations for each question, making it an essential study tool for mastering physics concepts and exam preparation.
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 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
Sociology