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Britain & the wider world: 1745 -1901
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1c the tudors: england, 1485-1603
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Physics
24 Dec 2025
640
3 pages
Emma Corden @emmacorden_rpll
Newton's laws of motion and momentum are fundamental concepts that explain how objects move and interact with each... Show more
Newton's laws form the foundation of how we understand motion. Newton's first law tells us that objects at rest stay at rest, and moving objects keep moving at constant speed unless something pushes or pulls them - think of a football rolling until friction stops it.
Newton's third law states that forces always come in pairs - when you push on something, it pushes back with equal strength. These action-reaction pairs are always equal and opposite, act along the same line, involve the same type of force, but affect different objects.
Linear momentum measures how hard it is to stop a moving object. The formula is simple momentum = mass × velocity. A heavy lorry moving slowly can have the same momentum as a light car moving quickly, which is why both can cause similar damage in crashes.
💡 Quick tip In a closed system (no external forces like friction), momentum is always conserved - the total momentum before a collision equals the total momentum after!
Newton's second law connects force to momentum changes the net force on an object equals the rate of change of its momentum . When mass stays constant, this becomes the familiar F = ma equation you've probably seen before.
Impulse is a brilliant concept that links force and time. It equals force multiplied by the time the force acts , and here's the key insight impulse equals change in momentum. This explains why airbags work - they increase collision time, reducing the average force on your body.
For changing forces, you calculate impulse as the area under a force-time graph. In triangular impacts, this becomes I = ½bh, where the base is time and height is maximum force.
💡 Remember When objects rebound (bounce back), the momentum change is doubled because the object reverses direction - so ΔP = 2mv rather than just mv.
Real-world collisions don't always happen in straight lines - balls bounce off walls at angles, cars crash at junctions, and snooker balls scatter across tables. Two-dimensional collisions require you to consider momentum in both horizontal and vertical directions separately.
For oblique impacts against walls, momentum parallel to the wall doesn't change if speed stays constant. However, momentum perpendicular to the wall changes by -2mv sin θ, where θ is the angle of impact.
When solving 2D collision problems, use Pythagoras' theorem and trigonometry. Break the momentum into components, apply conservation of momentum to each direction, then combine the results. The maths might look intimidating, but it's just careful application of the same principles.
💡 Pro strategy Always draw a clear diagram showing before and after velocities with their angles - it makes the vector calculations much easier to follow and reduces mistakes.
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.
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Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the key concepts of solids under stress, including Hooke's Law, stress and strain relationships, force-extension graphs, and the classification of materials. This summary covers dislocations, elastic potential energy, and the mechanical properties of crystalline and polymeric solids, providing a comprehensive overview for A-Level Physics students.
PhysicsExplore detailed solutions to the November 2021 Physics Paper 1, covering key concepts such as simple harmonic motion, gravitational potential energy, work-energy theorem, and more. This resource is ideal for students preparing for exams, providing clear explanations and step-by-step calculations for various physics problems.
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 the fundamentals of centripetal motion in this A Level Physics summary. Understand key concepts such as centripetal acceleration, angular velocity, and the forces involved in circular motion. Ideal for AQA students preparing for exams, this resource covers essential equations and principles of rotational dynamics.
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 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
Emma Corden
@emmacorden_rpll
Newton's laws of motion and momentum are fundamental concepts that explain how objects move and interact with each other. These principles govern everything from car crashes to rocket launches, making them essential for understanding the physical world around us.
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Newton's laws form the foundation of how we understand motion. Newton's first law tells us that objects at rest stay at rest, and moving objects keep moving at constant speed unless something pushes or pulls them - think of a football rolling until friction stops it.
Newton's third law states that forces always come in pairs - when you push on something, it pushes back with equal strength. These action-reaction pairs are always equal and opposite, act along the same line, involve the same type of force, but affect different objects.
Linear momentum measures how hard it is to stop a moving object. The formula is simple: momentum = mass × velocity. A heavy lorry moving slowly can have the same momentum as a light car moving quickly, which is why both can cause similar damage in crashes.
💡 Quick tip: In a closed system (no external forces like friction), momentum is always conserved - the total momentum before a collision equals the total momentum after!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Newton's second law connects force to momentum changes: the net force on an object equals the rate of change of its momentum . When mass stays constant, this becomes the familiar F = ma equation you've probably seen before.
Impulse is a brilliant concept that links force and time. It equals force multiplied by the time the force acts , and here's the key insight: impulse equals change in momentum. This explains why airbags work - they increase collision time, reducing the average force on your body.
For changing forces, you calculate impulse as the area under a force-time graph. In triangular impacts, this becomes I = ½bh, where the base is time and height is maximum force.
💡 Remember: When objects rebound (bounce back), the momentum change is doubled because the object reverses direction - so ΔP = 2mv rather than just mv.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Real-world collisions don't always happen in straight lines - balls bounce off walls at angles, cars crash at junctions, and snooker balls scatter across tables. Two-dimensional collisions require you to consider momentum in both horizontal and vertical directions separately.
For oblique impacts against walls, momentum parallel to the wall doesn't change if speed stays constant. However, momentum perpendicular to the wall changes by -2mv sin θ, where θ is the angle of impact.
When solving 2D collision problems, use Pythagoras' theorem and trigonometry. Break the momentum into components, apply conservation of momentum to each direction, then combine the results. The maths might look intimidating, but it's just careful application of the same principles.
💡 Pro strategy: Always draw a clear diagram showing before and after velocities with their angles - it makes the vector calculations much easier to follow and reduces mistakes.
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.
9
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the key concepts of solids under stress, including Hooke's Law, stress and strain relationships, force-extension graphs, and the classification of materials. This summary covers dislocations, elastic potential energy, and the mechanical properties of crystalline and polymeric solids, providing a comprehensive overview for A-Level Physics students.
PhysicsExplore detailed solutions to the November 2021 Physics Paper 1, covering key concepts such as simple harmonic motion, gravitational potential energy, work-energy theorem, and more. This resource is ideal for students preparing for exams, providing clear explanations and step-by-step calculations for various physics problems.
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 the fundamentals of centripetal motion in this A Level Physics summary. Understand key concepts such as centripetal acceleration, angular velocity, and the forces involved in circular motion. Ideal for AQA students preparing for exams, this resource covers essential equations and principles of rotational dynamics.
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 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