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1 Jan 2026

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Introduction to Physics: A Beginner's Guide

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evie

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Physics might seem intimidating at first, but it's actually about... Show more

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# General Physics # Standard Units

| Quantity              | Symbol | Unit                     | Unit Symbol |
| --------------------- | --

General Physics

Physics is everywhere in your daily life, and once you grasp the fundamentals, you'll start seeing it in action constantly. Whether you're dropping your keys, charging your phone, or listening to music, physics explains how it all works.

The key to succeeding in physics is mastering the basics first - standard units, understanding matter, and recognising circuit symbols. These building blocks will make everything else click into place much more easily.

Top Tip: Don't try to memorise everything at once - focus on understanding the patterns and relationships between different concepts.

# General Physics # Standard Units

| Quantity              | Symbol | Unit                     | Unit Symbol |
| --------------------- | --

Standard Units - The Basics

Every measurement in physics needs a proper unit, and learning these is like learning the alphabet before reading. You'll use these units constantly, so getting comfortable with them now will save you loads of time later.

Mass is measured in kilograms (kg) - that's how much stuff something contains. Weight, however, is the force pulling that mass down, measured in Newtons (N). Don't mix these up!

When things move, we measure their velocity in metres per second m/sm/s and their acceleration in metres per second squared m/s2m/s². Force also uses Newtons, whilst work done gets measured in Joules (J).

Remember: Weight and mass are different - your mass stays the same on the Moon, but your weight changes because gravity is weaker there!

# General Physics # Standard Units

| Quantity              | Symbol | Unit                     | Unit Symbol |
| --------------------- | --

More Standard Units You Need

These additional units might look more complex, but they're just as important for your physics toolkit. Gravitational field strength uses Newtons per kilogram N/kgN/kg - this tells you how strong gravity is pulling on each kilogram of mass.

For electrical concepts, potential difference (voltage) uses Volts (V), current flows in Amps (A), and resistance is measured in Ohms (Ω). Power gets measured in Watts (W) - the same unit you see on light bulbs.

Density uses kilograms per metre cubed kg/m3kg/m³, which tells you how much mass fits into each cubic metre. Think of it as how tightly packed the particles are in different materials.

Quick Check: Next time you see a light bulb, check its wattage - that's the power unit in action!

# General Physics # Standard Units

| Quantity              | Symbol | Unit                     | Unit Symbol |
| --------------------- | --

States of Matter Made Simple

Understanding states of matter is about picturing how particles behave differently as you heat or cool them. In solids, particles huddle very close together in neat, regular patterns, just vibrating gently in fixed positions with the lowest energy.

Liquids have particles that are still close but randomly arranged, giving them freedom to move around each other - that's why you can pour water but not ice. These particles have greater energy than in solids.

Gases have particles spread far apart, randomly arranged, and moving freely with the highest energy. This explains why gases expand to fill any container and why heating makes them move even faster.

Think About It: When you see steam rising from hot water, you're watching particles gain enough energy to change from liquid to gas!

# General Physics # Standard Units

| Quantity              | Symbol | Unit                     | Unit Symbol |
| --------------------- | --

Circuit Symbols Decoded

Circuit symbols are like a universal language that lets you read electrical diagrams without getting confused by realistic drawings. Each symbol represents a specific component, and once you know them, circuits become much clearer.

Basic symbols include cells and batteries for power, switches (open or closed), and resistors that slow down current flow. Variable resistors let you adjust the resistance, whilst voltmeters (V) and ammeters (A) measure electrical quantities.

Useful components include LEDs (light emitting diodes) that only let current flow one way, motors that convert electrical energy to movement, and LDRs (light dependent resistors) that change resistance based on light levels.

Pro Tip: When drawing circuits, always use the proper symbols rather than realistic pictures - it makes everything clearer and gets you better marks!



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4.8/5

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

 

Physics

173

1 Jan 2026

5 pages

Introduction to Physics: A Beginner's Guide

user profile picture

evie

@e777

Physics might seem intimidating at first, but it's actually about understanding the world around you - from why your phone battery dies to how sound travels through your headphones. Getting familiar with the basic units, particle behaviour, and circuit symbols... Show more

# General Physics # Standard Units

| Quantity              | Symbol | Unit                     | Unit Symbol |
| --------------------- | --

Sign up to see the contentIt's free!

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General Physics

Physics is everywhere in your daily life, and once you grasp the fundamentals, you'll start seeing it in action constantly. Whether you're dropping your keys, charging your phone, or listening to music, physics explains how it all works.

The key to succeeding in physics is mastering the basics first - standard units, understanding matter, and recognising circuit symbols. These building blocks will make everything else click into place much more easily.

Top Tip: Don't try to memorise everything at once - focus on understanding the patterns and relationships between different concepts.

# General Physics # Standard Units

| Quantity              | Symbol | Unit                     | Unit Symbol |
| --------------------- | --

Sign up to see the contentIt's free!

Access to all documents

Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

Standard Units - The Basics

Every measurement in physics needs a proper unit, and learning these is like learning the alphabet before reading. You'll use these units constantly, so getting comfortable with them now will save you loads of time later.

Mass is measured in kilograms (kg) - that's how much stuff something contains. Weight, however, is the force pulling that mass down, measured in Newtons (N). Don't mix these up!

When things move, we measure their velocity in metres per second m/sm/s and their acceleration in metres per second squared m/s2m/s². Force also uses Newtons, whilst work done gets measured in Joules (J).

Remember: Weight and mass are different - your mass stays the same on the Moon, but your weight changes because gravity is weaker there!

# General Physics # Standard Units

| Quantity              | Symbol | Unit                     | Unit Symbol |
| --------------------- | --

Sign up to see the contentIt's free!

Access to all documents

Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

More Standard Units You Need

These additional units might look more complex, but they're just as important for your physics toolkit. Gravitational field strength uses Newtons per kilogram N/kgN/kg - this tells you how strong gravity is pulling on each kilogram of mass.

For electrical concepts, potential difference (voltage) uses Volts (V), current flows in Amps (A), and resistance is measured in Ohms (Ω). Power gets measured in Watts (W) - the same unit you see on light bulbs.

Density uses kilograms per metre cubed kg/m3kg/m³, which tells you how much mass fits into each cubic metre. Think of it as how tightly packed the particles are in different materials.

Quick Check: Next time you see a light bulb, check its wattage - that's the power unit in action!

# General Physics # Standard Units

| Quantity              | Symbol | Unit                     | Unit Symbol |
| --------------------- | --

Sign up to see the contentIt's free!

Access to all documents

Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

States of Matter Made Simple

Understanding states of matter is about picturing how particles behave differently as you heat or cool them. In solids, particles huddle very close together in neat, regular patterns, just vibrating gently in fixed positions with the lowest energy.

Liquids have particles that are still close but randomly arranged, giving them freedom to move around each other - that's why you can pour water but not ice. These particles have greater energy than in solids.

Gases have particles spread far apart, randomly arranged, and moving freely with the highest energy. This explains why gases expand to fill any container and why heating makes them move even faster.

Think About It: When you see steam rising from hot water, you're watching particles gain enough energy to change from liquid to gas!

# General Physics # Standard Units

| Quantity              | Symbol | Unit                     | Unit Symbol |
| --------------------- | --

Sign up to see the contentIt's free!

Access to all documents

Improve your grades

Join milions of students

By signing up you accept Terms of Service and Privacy Policy

Circuit Symbols Decoded

Circuit symbols are like a universal language that lets you read electrical diagrams without getting confused by realistic drawings. Each symbol represents a specific component, and once you know them, circuits become much clearer.

Basic symbols include cells and batteries for power, switches (open or closed), and resistors that slow down current flow. Variable resistors let you adjust the resistance, whilst voltmeters (V) and ammeters (A) measure electrical quantities.

Useful components include LEDs (light emitting diodes) that only let current flow one way, motors that convert electrical energy to movement, and LDRs (light dependent resistors) that change resistance based on light levels.

Pro Tip: When drawing circuits, always use the proper symbols rather than realistic pictures - it makes everything clearer and gets you better marks!

We thought you’d never ask...

What is the Knowunity AI companion?

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.

Where can I download the Knowunity app?

You can download the app from Google Play Store and 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 in Physics

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Can't find what you're looking for? Explore other subjects.

Students love us — and so will you.

4.9/5

App Store

4.8/5

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