Subjects
Maths
Chemistry
Biology
English Language
History
Responding to change (a2 only)
Infection and response
Homeostasis and response
Energy transfers (a2 only)
Cell biology
Organisms respond to changes in their internal and external environments (a-level only)
Biological molecules
Organisation
Substance exchange
Bioenergetics
Genetic information & variation
Inheritance, variation and evolution
Genetics & ecosystems (a2 only)
Ecology
Cells
Show all topics
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
World war one
Britain: 1509 -1745
Show all topics
Physics
4 Dec 2025
216
3 pages
Sofia @sofia_mnlj
Understanding motion is crucial in physics - it's literally how everything around you moves! This topic covers the... Show more
Ever wondered why physicists are so fussy about direction? It's because some measurements need it, whilst others don't! Vector quantities have both size (magnitude) and direction - think of force, displacement, velocity, and momentum.
Scalar quantities only have size, no direction needed. These include mass, speed, distance, energy, and time. For example, saying "I walked 100m north" describes displacement (vector), but "I walked 100m" describes distance (scalar).
Here's something that trips many students up displacement is the straight-line distance between your start and end points, whilst distance is the actual path you travelled. Because of curves and bends, displacement is usually less than the total distance covered.
Quick Check Weight is a force that always acts towards Earth's centre - that's why it's a vector quantity measured in Newtons!
Calculating speed is straightforward once you know the formula speed = distance ÷ time. This gives you metres per second , which you can rearrange to find distance travelled = speed × time.
For really fast-moving objects, scientists use light gates instead of stopwatches because they're much more accurate. You can also find speed from the gradient (slope) of a distance-time graph - the steeper the line, the faster the object.
Acceleration measures how quickly velocity changes, using the formula acceleration = ÷ time. Remember, acceleration doesn't always mean getting faster - objects can decelerate (slow down) too!
Remember Velocity is speed with direction, so even if a car maintains constant speed around a corner, it's still accelerating because its direction changes!
There's a powerful equation that connects velocity, acceleration, and distance (final velocity)² - (initial velocity)² = 2 × acceleration × distance. This is brilliant for solving problems when you don't know the time taken.
Gravity provides constant acceleration here on Earth - approximately 9.8 m/s² . This means any falling object speeds up by about 10 m/s every second, assuming no air resistance interferes.
Velocity-time graphs tell amazing stories about motion. A horizontal line shows constant velocity, whilst slopes show acceleration or deceleration. The area under the line gives you the total displacement travelled.
Top Tip Don't confuse speed (scalar) with velocity (vector) - a car going around a roundabout at constant speed is actually changing velocity because its direction keeps changing!
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.
6
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore key concepts in motion and mechanics, including speed, velocity, acceleration, and kinematics. This summary covers distance-time and velocity-time graphs, average velocity calculations, and the relationship between speed and acceleration. Ideal for GCSE Physics revision.
PhysicsExplore the concepts of stopping distance and terminal velocity in physics. This summary covers key factors affecting thinking and braking distances, the role of air resistance, and the stages of free fall. Ideal for students studying motion and mechanics.
PhysicsExplore essential practical tasks for AQA GCSE Physics and Combined Science. This summary covers key experiments on force and acceleration, wave properties, Hooke's Law, reflection, refraction, and infrared radiation. Ideal for exam preparation, it includes setup instructions, calculations, and analysis methods to enhance understanding of core physics concepts.
PhysicsExplore the fundamental concepts of speed, velocity, and acceleration in physics. This summary covers key definitions, formulas, and examples, including scalar and vector quantities, kinematic equations, and how to calculate acceleration. Ideal for KS3 to GCSE students looking to strengthen their understanding of motion.
PhysicsExplore key concepts in kinematics, including distance, displacement, speed, velocity, and acceleration. This summary covers essential equations, graphical interpretations, and real-world applications, tailored for AQA GCSE Physics students. Understand how to calculate and differentiate between scalar and vector quantities, and learn to analyze motion through distance-time and velocity-time graphs.
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
Sofia
@sofia_mnlj
Understanding motion is crucial in physics - it's literally how everything around you moves! This topic covers the essential concepts of vectors, scalars, speed, velocity, and acceleration that you'll need to master for your GCSE Physics exams.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Ever wondered why physicists are so fussy about direction? It's because some measurements need it, whilst others don't! Vector quantities have both size (magnitude) and direction - think of force, displacement, velocity, and momentum.
Scalar quantities only have size, no direction needed. These include mass, speed, distance, energy, and time. For example, saying "I walked 100m north" describes displacement (vector), but "I walked 100m" describes distance (scalar).
Here's something that trips many students up: displacement is the straight-line distance between your start and end points, whilst distance is the actual path you travelled. Because of curves and bends, displacement is usually less than the total distance covered.
Quick Check: Weight is a force that always acts towards Earth's centre - that's why it's a vector quantity measured in Newtons!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Calculating speed is straightforward once you know the formula: speed = distance ÷ time. This gives you metres per second , which you can rearrange to find distance travelled = speed × time.
For really fast-moving objects, scientists use light gates instead of stopwatches because they're much more accurate. You can also find speed from the gradient (slope) of a distance-time graph - the steeper the line, the faster the object.
Acceleration measures how quickly velocity changes, using the formula: acceleration = ÷ time. Remember, acceleration doesn't always mean getting faster - objects can decelerate (slow down) too!
Remember: Velocity is speed with direction, so even if a car maintains constant speed around a corner, it's still accelerating because its direction changes!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
There's a powerful equation that connects velocity, acceleration, and distance: (final velocity)² - (initial velocity)² = 2 × acceleration × distance. This is brilliant for solving problems when you don't know the time taken.
Gravity provides constant acceleration here on Earth - approximately 9.8 m/s² . This means any falling object speeds up by about 10 m/s every second, assuming no air resistance interferes.
Velocity-time graphs tell amazing stories about motion. A horizontal line shows constant velocity, whilst slopes show acceleration or deceleration. The area under the line gives you the total displacement travelled.
Top Tip: Don't confuse speed (scalar) with velocity (vector) - a car going around a roundabout at constant speed is actually changing velocity because its direction keeps changing!
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.
6
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore key concepts in motion and mechanics, including speed, velocity, acceleration, and kinematics. This summary covers distance-time and velocity-time graphs, average velocity calculations, and the relationship between speed and acceleration. Ideal for GCSE Physics revision.
PhysicsExplore the concepts of stopping distance and terminal velocity in physics. This summary covers key factors affecting thinking and braking distances, the role of air resistance, and the stages of free fall. Ideal for students studying motion and mechanics.
PhysicsExplore essential practical tasks for AQA GCSE Physics and Combined Science. This summary covers key experiments on force and acceleration, wave properties, Hooke's Law, reflection, refraction, and infrared radiation. Ideal for exam preparation, it includes setup instructions, calculations, and analysis methods to enhance understanding of core physics concepts.
PhysicsExplore the fundamental concepts of speed, velocity, and acceleration in physics. This summary covers key definitions, formulas, and examples, including scalar and vector quantities, kinematic equations, and how to calculate acceleration. Ideal for KS3 to GCSE students looking to strengthen their understanding of motion.
PhysicsExplore key concepts in kinematics, including distance, displacement, speed, velocity, and acceleration. This summary covers essential equations, graphical interpretations, and real-world applications, tailored for AQA GCSE Physics students. Understand how to calculate and differentiate between scalar and vector quantities, and learn to analyze motion through distance-time and velocity-time graphs.
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