•

4 Jan 2026

•

6 pages

Exploring the Basics of Energy

Scarlett Edwardes

@scarlett_1917

Physics is all about how energy behaves in our world.... Show more

1 / 6

Energy Stores and Transfers

Energy is one of the most fundamental concepts in physics that you'll use throughout your studies. The most important thing to remember is that energy is never created or destroyed—it simply changes form.

Energy exists in various stores including thermal (internal), kinetic, gravitational potential, elastic potential, chemical, magnetic, nuclear, and electrostatic. When energy moves from one store to another, we call this a transfer.

Energy transfers happen in four main ways: mechanically (through forces doing work), electronically (by moving charges), heating (work done by heat), and radiation (work done by light or sound).

Remember this! When energy moves from one store to another, physicists call this "work done." This concept will appear repeatedly in your exams.

Gravitational Potential Energy

When you lift an object upwards, you're transferring energy into its gravitational potential energy (GPE) store. The higher you lift it, the more energy is stored.

This happens because the object exists in Earth's gravitational field, and energy is needed to work against this force. The amount of GPE depends on three factors: the object's mass, its height, and the strength of the gravitational field.

We calculate changes in GPE using the formula: Ep = mgh where m is mass in kg, g is gravitational field strength in N/kg, and h is height in meters.

Quick fact: The gravitational field strength on Earth is approximately 10 N/kg. This value makes calculations in your exams much easier!

Kinetic Energy

Kinetic energy is the energy an object has due to its motion. Energy transfers into the kinetic store when an object speeds up and transfers away when it slows down.

The amount of energy in this store depends on both the object's mass and its speed, calculated using: Ek = ½mv² where m is mass in kg and v is speed in m/s. Notice that doubling the speed quadruples the kinetic energy!

When an object falls, energy transfers between gravitational potential energy and kinetic energy stores. With no air resistance, the energy lost from the GPE store equals the energy gained in the kinetic store—this is conservation of energy in action.

Important: In real-world situations, air resistance causes some energy to be transferred to the thermal store of the surroundings instead of just to kinetic energy. This is why falling objects reach a terminal velocity.

Elastic Potential Energy

Elastic potential energy is stored when you stretch or compress objects like springs. Think about pulling back a catapult or stretching a rubber band—you're storing energy!

As long as you don't stretch beyond the limit of proportionality (where the object's behavior changes), elastic potential energy can be calculated using: Ee = ½ke² where k is the spring constant in N/m and e is extension in m.

The spring constant tells us how stiff a spring is—a higher value means a stiffer spring that's harder to stretch but stores more energy for the same extension.

Key concept: The limit of proportionality marks where Hooke's Law $F=ke$ stops working. Before this point, extension is directly proportional to the force applied. This relationship appears regularly in exam questions!

Thermal Energy and Specific Heat Capacity

Thermal energy (also called internal energy) is the total kinetic energy of all particles in an object. It's what we're really talking about when we discuss temperature—the more energetic the particles, the higher the temperature.

Different materials require different amounts of energy to heat up. Specific heat capacity measures how much energy (in joules) is needed to raise the temperature of 1kg of a substance by 1°C.

We calculate changes in thermal energy using: E = mc∆θ where E is energy in joules, m is mass in kg, c is specific heat capacity in J/kg°C, and ∆θ is the temperature change in °C.

Practical application: Materials with high specific heat capacity (like water) are excellent for storing thermal energy, which is why they're used in heating systems. This concept helps explain why coastal areas have milder climates than inland regions.

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.

Most popular content in Physics

GCSE Physics: Energy & Radioactivity

Explore key concepts in GCSE Physics, including energy types, power calculations, radioactive decay (alpha, beta, gamma), and electrical circuits. This summary covers essential topics such as conservation of energy, resistance, and the National Grid, providing a comprehensive overview for exam preparation.

Physics

BTEC Applied Science Unit 1 Overview

Comprehensive resource for Year 12 students pursuing a Level 3 Diploma in Applied Science. This booklet covers essential topics including cell structure, chemical properties, and wave theory, providing clear explanations and key concepts to aid in your studies and exam preparation.

Chemistry

Forces and Motion Overview

Explore key concepts in Forces and Motion, including Hooke's Law, velocity, acceleration, and the principles of moments. This summary covers essential topics such as the relationship between force and extension, terminal velocity, and the impact of safety devices in physics. Ideal for AQA Physics Unit 5 revision.

Physics

AQA Physics Paper 1 Overview

Comprehensive summary of key concepts in AQA Physics Paper 1, covering atomic structure, energy transfers, radioactivity, electrical circuits, and more. Ideal for exam preparation and revision. Topics include nuclear fission, half-life, specific latent heat, and the particle model.

Physics

Electricity Fundamentals

Comprehensive GCSE AQA Physics notes covering key concepts of electricity, including series and parallel circuits, power calculations, resistance, electrostatics, and the National Grid. Ideal for students preparing for exams, this resource provides clear explanations and essential formulas.

Physics

Physics Paper 2 Essentials

Master key concepts for AQA Combined Physics Paper 2, including electromagnetic waves, mechanics, forces, and motion. This comprehensive summary covers essential topics like wave properties, Newton's laws, and the motor effect, ensuring you're well-prepared for your exam.

Physics

Energy Transfers in Physics

Explore the principles of energy transfer, including gravitational potential energy, kinetic energy, and elastic potential energy. This summary covers key concepts such as work done, efficiency, and the impact of friction on energy dissipation. Ideal for GCSE AQA Physics students seeking to understand energy transformations and conservation.

Physics

Understanding Radioactivity

Explore the key concepts of radioactivity, including nuclear fission, decay types (alpha, beta, gamma), and detection methods like Geiger-Müller counters. This comprehensive summary covers essential topics for GCSE Physics, including isotopes, half-life, and practical applications in medicine and safety.

Physics

GCSE Physics Practical Experiments

Explore essential GCSE Physics practicals for AQA, covering key concepts such as Hooke's Law, wave properties, thermal insulation, and electrical circuits. This comprehensive guide includes step-by-step procedures, variables, and safety considerations for each experiment, ensuring a thorough understanding of practical applications in physics.

Physics

Most popular content

An Inspector Calls: Character Insights

Explore in-depth analysis and key quotes for characters in J.B. Priestley's 'An Inspector Calls'. This resource covers Gerald Croft, Inspector Goole, Sheila Birling, Mrs. Birling, Eric Birling, and Eva Smith, focusing on themes of class, gender roles, and social responsibility. Ideal for students aiming for Grade 8 and above.

English Literature

aqa higher tier combined science - biology b1 : cell biology, paper 1

b1: cell biology - paper 1

Biology

Sociology of Families: Comprehensive Revision

Dive into an extensive overview of family dynamics, perspectives, and patterns in sociology. This resource covers key concepts such as family diversity, gender roles, marriage, and the impact of social policies on family structures. Perfect for A-Level Sociology students preparing for Paper 2.

Sociology

Comprehensive Crime & Deviance Overview

Explore an extensive revision of crime and deviance topics, including theories, types of crime, and the impact of media. This resource covers key concepts such as Marxism, functionalism, gender and crime, and the influence of globalization on criminal behavior. Ideal for students seeking a thorough understanding of criminology and its various theories. Type: Full Topic Revision.

Sociology

Sociology of Education Overview

Explore comprehensive A-Level Sociology notes on the education system, covering key theories, policies, and sociological perspectives. This resource includes insights on marketisation, gender roles, cultural deprivation, and educational inequalities, providing a thorough understanding of how education shapes social stratification and individual achievement. Ideal for exam preparation and in-depth study.

Sociology

Criminal Justice Evidence Rules

Explore the essential rules governing the use of evidence in criminal cases, including reliability, admissibility, and relevance. This summary covers key concepts such as the roles of personnel in investigations, the impact of witness testimonies, and the implications of plea bargaining. Ideal for Year 13 criminology students preparing for assessments.

Criminology

Biology Paper 1 Overview

Comprehensive study notes covering key concepts in cellular biology, human digestion, respiration, photosynthesis, and the circulatory system. This resource includes detailed explanations of cell structures, enzyme functions, nutrient absorption, and the impact of environmental factors on biological processes. Ideal for students preparing for Biology Paper 1 exams.

Biology

Macbeth: Guilt and Ambition

Explore the complex themes of guilt and ambition in Shakespeare's 'Macbeth'. This analysis covers key characters, including Macbeth and Lady Macbeth, their moral dilemmas, and the tragic consequences of their ambition. Ideal for students studying character motivations, thematic elements, and the psychological impact of power. Includes insights on the natural order, manipulation, and the descent into madness.

English Literature

Language Paper 1 Strategies

Master the AQA English Language Paper 1 with this comprehensive guide. Explore key strategies for language and structural analysis, critical evaluation, and creative writing. Learn how to effectively analyze texts, utilize literary techniques, and enhance your writing skills to excel in your exams.

English Language

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

Stefan S

iOS user

Samantha Klich

Android user

Anna

iOS user

Best app on earth! no words because it’s too good

Thomas R

iOS user

Basil

Android user

David K

iOS user

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

Rohan U

Android user

Xander S

iOS user

Elisha

iOS user

Paul T

iOS user

Physics

•

187

•

4 Jan 2026

•

6 pages

Exploring the Basics of Energy

Scarlett Edwardes

@scarlett_1917

Physics is all about how energy behaves in our world. Energy never disappears but constantly moves between different stores through various transfer methods. Understanding these energy stores and their mathematical relationships is key to mastering many physics concepts.

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

Energy Stores and Transfers

Energy transfers happen in four main ways: mechanically (through forces doing work), electronically (by moving charges), heating (work done by heat), and radiation (work done by light or sound).

Remember this! When energy moves from one store to another, physicists call this "work done." This concept will appear repeatedly in your exams.

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

Gravitational Potential Energy

When you lift an object upwards, you're transferring energy into its gravitational potential energy (GPE) store. The higher you lift it, the more energy is stored.

We calculate changes in GPE using the formula: Ep = mgh where m is mass in kg, g is gravitational field strength in N/kg, and h is height in meters.

Quick fact: The gravitational field strength on Earth is approximately 10 N/kg. This value makes calculations in your exams much easier!

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

Kinetic Energy

Kinetic energy is the energy an object has due to its motion. Energy transfers into the kinetic store when an object speeds up and transfers away when it slows down.

Important: In real-world situations, air resistance causes some energy to be transferred to the thermal store of the surroundings instead of just to kinetic energy. This is why falling objects reach a terminal velocity.

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

Elastic Potential Energy

Elastic potential energy is stored when you stretch or compress objects like springs. Think about pulling back a catapult or stretching a rubber band—you're storing energy!

The spring constant tells us how stiff a spring is—a higher value means a stiffer spring that's harder to stretch but stores more energy for the same extension.

Key concept: The limit of proportionality marks where Hooke's Law $F=ke$ stops working. Before this point, extension is directly proportional to the force applied. This relationship appears regularly in exam questions!

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

Thermal Energy and Specific Heat Capacity

Different materials require different amounts of energy to heat up. Specific heat capacity measures how much energy (in joules) is needed to raise the temperature of 1kg of a substance by 1°C.

We calculate changes in thermal energy using: E = mc∆θ where E is energy in joules, m is mass in kg, c is specific heat capacity in J/kg°C, and ∆θ is the temperature change in °C.

Practical application: Materials with high specific heat capacity (like water) are excellent for storing thermal energy, which is why they're used in heating systems. This concept helps explain why coastal areas have milder climates than inland regions.

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