Equations of motion are essential tools in physics that help...
Physics42 views·Updated Jun 15, 2026·2 pagesMotion Equations for Physics - A2 Level Notes
P
Pasindi Lahandapurage@pasindilahandapurage_kqvo
1
of 2
Understanding the Equations of Motion
Before diving into the equations, let's clarify what each symbol represents. In physics, we use displacement (s) measured in meters, initial velocity (u) and final velocity (v) in meters per second, acceleration (a) in meters per second squared, and time (t) in seconds.
The first equation of motion comes from the basic definition of acceleration. Since acceleration is the rate of change in velocity, we can write it as a = /t. Rearranging this gives us Equation 1: v = u + at. This formula lets you calculate the final velocity when you know the initial velocity, acceleration, and time.
Equation 2 deals with displacement using average velocity. When an object accelerates, its velocity changes constantly. The average velocity is /2, so the displacement formula becomes s = t/2. This equation is particularly useful when you need to find displacement without knowing acceleration.
💡 Think of these equations as your physics toolbox. You don't need to memorize how they're derived - just know when to apply each one. The key is identifying which variables you have and which one you need to find.
Equation 3: s = ut + ½at² comes from combining Equations 1 and 2. You can also visualize this as the area under a velocity-time graph, where displacement equals the sum of a rectangle (ut) and a triangle (½at²).
2
of 2
Completing the Motion Toolkit
The final equation of motion eliminates time from the variables. By substituting t = /a from Equation 1 into Equation 2, we get Equation 4: v² = u² + 2as. This powerful formula relates displacement directly to initial and final velocities without needing to know time.
These four equations of motion form a complete system for analyzing uniform acceleration problems. The beauty of this system is that you only need to know three variables to find the fourth. Just identify what information you have and what you're looking for, then select the appropriate equation.
Remember that these equations only apply to situations with uniform acceleration - where the rate of change in velocity remains constant throughout the motion. Most basic physics problems like free fall, projectile motion, and simple car acceleration fit this model.
⚠️ Always check your units before solving problems! Displacement should be in meters, velocities in m/s, acceleration in m/s², and time in seconds. Mixing units will lead to incorrect answers.
With practice, you'll quickly develop the intuition to select the right equation for any motion problem. Don't worry if it seems challenging at first - everyone improves with practice!
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Physics42 views·Updated Jun 15, 2026·2 pagesMotion Equations for Physics - A2 Level Notes
P
Pasindi Lahandapurage@pasindilahandapurage_kqvo
Equations of motion are essential tools in physics that help us analyze how objects move under uniform acceleration. These equations relate five key variables: displacement, initial velocity, final velocity, acceleration, and time. Understanding how to use them will help you...
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Understanding the Equations of Motion
Before diving into the equations, let's clarify what each symbol represents. In physics, we use displacement (s) measured in meters, initial velocity (u) and final velocity (v) in meters per second, acceleration (a) in meters per second squared, and time (t) in seconds.
The first equation of motion comes from the basic definition of acceleration. Since acceleration is the rate of change in velocity, we can write it as a = /t. Rearranging this gives us Equation 1: v = u + at. This formula lets you calculate the final velocity when you know the initial velocity, acceleration, and time.
Equation 2 deals with displacement using average velocity. When an object accelerates, its velocity changes constantly. The average velocity is /2, so the displacement formula becomes s = t/2. This equation is particularly useful when you need to find displacement without knowing acceleration.
💡 Think of these equations as your physics toolbox. You don't need to memorize how they're derived - just know when to apply each one. The key is identifying which variables you have and which one you need to find.
Equation 3: s = ut + ½at² comes from combining Equations 1 and 2. You can also visualize this as the area under a velocity-time graph, where displacement equals the sum of a rectangle (ut) and a triangle (½at²).
2
of 2Sign up to see the content. It's free!
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Completing the Motion Toolkit
The final equation of motion eliminates time from the variables. By substituting t = /a from Equation 1 into Equation 2, we get Equation 4: v² = u² + 2as. This powerful formula relates displacement directly to initial and final velocities without needing to know time.
These four equations of motion form a complete system for analyzing uniform acceleration problems. The beauty of this system is that you only need to know three variables to find the fourth. Just identify what information you have and what you're looking for, then select the appropriate equation.
Remember that these equations only apply to situations with uniform acceleration - where the rate of change in velocity remains constant throughout the motion. Most basic physics problems like free fall, projectile motion, and simple car acceleration fit this model.
⚠️ Always check your units before solving problems! Displacement should be in meters, velocities in m/s, acceleration in m/s², and time in seconds. Mixing units will lead to incorrect answers.
With practice, you'll quickly develop the intuition to select the right equation for any motion problem. Don't worry if it seems challenging at first - everyone improves with practice!
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.
Where can I download the Knowunity app?
You can download the app in the Google Play Store and in the Apple App Store.
Is Knowunity really free of charge?
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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Most popular content: Uniform Motion
1Most popular content in Physics
9P
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36613
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This presentation offers an explanation of simple machines and how to solve for mechanical advantage, ideal mechanical advantage, and efficiency of each machine. It also provides definitions and examples.
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Analyze the initial social and religious encounters between Europeans, Africans, and Indigenous peoples in the colonial Americas.
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Analyze the environmental factors and technological innovations that led to the rise of early states in Mesopotamia, Egypt, and the Indus Valley.
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Samantha KlichAndroid 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.
AnnaiOS user