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Physics
12 Dec 2025
188
2 pages
Zofia @zofia_577
Understanding how things move and change speed is crucial for physics - and it's everywhere around you! From... Show more
Velocity isn't just about how fast something's moving - it's speed with a specific direction attached. This makes it what physicists call a vector quantity, which means direction matters just as much as the number.
When you're calculating velocity, you need two key pieces of information. First, measure the distance travelled in a straight line from start to finish (not the winding path taken). Second, note the direction of that straight line - north, south, or at a specific angle.
Quick Tip Remember that 30 m/s east is completely different from 30 m/s west, even though the speeds are identical!
This is why velocity problems often feel trickier than basic speed calculations - you're juggling both magnitude and direction simultaneously.
Acceleration measures how quickly velocity changes over time - think of it as the rate your speed increases or decreases. The beauty of acceleration is that it follows a straightforward pattern you can master with practice.
Start with the change in velocity final velocity minus initial velocity. Then divide this change by the time taken. The formula becomes a = Δv/t, where acceleration (a) is measured in metres per second squared .
Let's see this in action with a car accelerating from rest to 28 m/s in 8.0 seconds. Since it starts from rest, initial velocity = 0 m/s. Change in velocity = 28 - 0 = 28 m/s. Therefore acceleration = 28/8 = 3.5 m/s².
Remember When an object starts "from rest," its initial velocity is always 0 m/s - this simplifies your calculations significantly!
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 key principles of forces and motion, including Newton's Laws, momentum, and braking distance. This summary covers essential equations, factors affecting braking, and the relationship between force, mass, and acceleration. Ideal for GCSE Physics revision.
PhysicsExplore essential concepts in Physics related to forces, including static equilibrium, kinetic energy, momentum, and Newton's Laws of Motion. This comprehensive booklet features past paper questions and mark schemes to help identify and strengthen your understanding of key topics. Ideal for students preparing for exams in AQA Physics.
PhysicsExplore the fundamental concepts of kinematics and forces in physics, including scalar and vector quantities, Newton's Laws of Motion, and key equations for speed, acceleration, and weight. This summary provides essential insights for understanding motion and mechanics, ideal for Edexcel Physics Paper 1 preparation.
PhysicsExplore the fundamental differences between speed and velocity, including scalar and vector quantities. This summary covers key concepts such as distance, displacement, and the calculations for determining speed and velocity. Ideal for students seeking clarity on these essential physics topics.
PhysicsExplore key concepts in Forces and Motion, including Acceleration, Circular Motion, Freefall, Speed & Velocity, Newton’s Laws, Kinetic Energy, and Momentum. This summary covers essential topics such as Stopping Distance, Inertial Mass, and the effects of forces on motion, providing a comprehensive understanding for physics students.
PhysicsExplore the principles of momentum, including linear momentum, types of collisions (elastic and inelastic), and the conservation of momentum in closed systems. This summary provides essential insights for Edexcel Physics Paper 1, focusing on key concepts and formulas related to momentum and its applications.
PhysicsQuotes from every main character
English LiteratureApp 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
Zofia
@zofia_577
Understanding how things move and change speed is crucial for physics - and it's everywhere around you! From cars accelerating away from traffic lights to footballs flying through the air, velocity and acceleration help explain the motion you see every... Show more
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Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Velocity isn't just about how fast something's moving - it's speed with a specific direction attached. This makes it what physicists call a vector quantity, which means direction matters just as much as the number.
When you're calculating velocity, you need two key pieces of information. First, measure the distance travelled in a straight line from start to finish (not the winding path taken). Second, note the direction of that straight line - north, south, or at a specific angle.
Quick Tip: Remember that 30 m/s east is completely different from 30 m/s west, even though the speeds are identical!
This is why velocity problems often feel trickier than basic speed calculations - you're juggling both magnitude and direction simultaneously.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Acceleration measures how quickly velocity changes over time - think of it as the rate your speed increases or decreases. The beauty of acceleration is that it follows a straightforward pattern you can master with practice.
Start with the change in velocity: final velocity minus initial velocity. Then divide this change by the time taken. The formula becomes: a = Δv/t, where acceleration (a) is measured in metres per second squared .
Let's see this in action with a car accelerating from rest to 28 m/s in 8.0 seconds. Since it starts from rest, initial velocity = 0 m/s. Change in velocity = 28 - 0 = 28 m/s. Therefore: acceleration = 28/8 = 3.5 m/s².
Remember: When an object starts "from rest," its initial velocity is always 0 m/s - this simplifies your calculations significantly!
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.
7
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore key principles of forces and motion, including Newton's Laws, momentum, and braking distance. This summary covers essential equations, factors affecting braking, and the relationship between force, mass, and acceleration. Ideal for GCSE Physics revision.
PhysicsExplore essential concepts in Physics related to forces, including static equilibrium, kinetic energy, momentum, and Newton's Laws of Motion. This comprehensive booklet features past paper questions and mark schemes to help identify and strengthen your understanding of key topics. Ideal for students preparing for exams in AQA Physics.
PhysicsExplore the fundamental concepts of kinematics and forces in physics, including scalar and vector quantities, Newton's Laws of Motion, and key equations for speed, acceleration, and weight. This summary provides essential insights for understanding motion and mechanics, ideal for Edexcel Physics Paper 1 preparation.
PhysicsExplore the fundamental differences between speed and velocity, including scalar and vector quantities. This summary covers key concepts such as distance, displacement, and the calculations for determining speed and velocity. Ideal for students seeking clarity on these essential physics topics.
PhysicsExplore key concepts in Forces and Motion, including Acceleration, Circular Motion, Freefall, Speed & Velocity, Newton’s Laws, Kinetic Energy, and Momentum. This summary covers essential topics such as Stopping Distance, Inertial Mass, and the effects of forces on motion, providing a comprehensive understanding for physics students.
PhysicsExplore the principles of momentum, including linear momentum, types of collisions (elastic and inelastic), and the conservation of momentum in closed systems. This summary provides essential insights for Edexcel Physics Paper 1, focusing on key concepts and formulas related to momentum and its applications.
PhysicsQuotes from every main character
English LiteratureApp 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