Energy is what makes things happen around us, like making a car move or turning on a light bulb. Energy is all around us, and it comes in many forms, such as light, heat, sound, or movement. When we use energy, it doesn't disappear or get destroyed. Instead, it is transferred from one object or energy store to another.

Think of a battery-powered toy car. When you turn it on, the battery provides energy to the car's motor, which makes it move. The energy stored in the battery is now transferred to the car's motor, which then converts it into movement.

As the car moves, it loses some of its energy to friction with the ground, the air, and other surfaces. This lost energy is also transferred to other objects and energy stores, such as the air molecules, the ground, or the car's internal parts, where it might be converted into heat or sound energy.

So, in this way, energy is never used up, but rather it is just transferred from one object to another or from one energy store to another. This is known as the law of conservation of energy, which says that energy cannot be created or destroyed, only transferred or transformed from one form to another. This means that we can't make energy out of anything, but we can change it from one form to another, like transforming the chemical energy stored in food into the kinetic energy that we use to move our bodies.



Energy is transferred

When energy is transferred to an object, it gets stored in one of its object’s energy stores.

If you're looking to use energy in your life, you need to know about the following types of energy stores:

TYPES OF ENERGY STORES

It's important to be aware of the different energy stores, including:

1. Kinetic energy stores.
2. Thermal energy stores.
3. Gravitational energy stores.
4. Magnetic energy stores.
5. Elastic energy stores.
6. Chemical energy stores.
7. Electrostatic energy stores.
8. Nuclear energy stores.

The transfer of energy is a fundamental part of everyday life. It can be accomplished in various ways, such as mechanically through applying a force, electrically through the movement of charged particles, or by heating and radiating light or sound. Each method has its own unique benefits and drawbacks, which must be taken into account when considering the most efficient way to transfer energy.



System changes transfer energy

A system can be a single item, such as the air in a piston, or multiple or a group of items that are associated with each other, like two colliding vehicles. Essentially, it is just another word for something you are studying or observing.
Whenever a system undergoes changes, energy is transferred in several ways. This transfer can either be into or away from the system; it may also involve energy being exchanged between objects within the system or different forms of energy, such as kinetic and thermal energy.
Closed systems are self-contained, where no matter or energy can be transferred. It isn't based on how much energy is available in the system, it will always remain constant, and the net change in the system's total energy will always remain zero.


Heat can transfer energy

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A great demonstration of this concept is boiling water in a kettle. The water itself can be seen as the system, where energy is transferred from the heating element to the thermal energy stored in the water. A result of this is an increase in water temperature.
Energy is transferred by heating: boiling kettle
Energy is transferred by heating: boiling kettle
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We can also view the kettle and water as a two-part system. First, the heating element receives electricity via electricity, which is then converted to thermal energy and transferred to the water's thermal store. This process allows for efficient heating of the water.

Energy is the backbone of the universe, and understanding it in different forms is essential. Energy can be stored in various ways, from hot objects to chemical bonds.

To effectively discuss energy in an exam, one must refer to it in terms of the energy store it's in. For instance, when discussing energy contained by a hot object, one should refer to it as having 'energy stored in the thermal form'. This will help you as a student accurately describe your understanding of energy and its associated terminology.



Revision Quiz for Energy Stores

To answer the questions correctly, hover over each option and click to select it. After you finish, click 'Submit' to check your score and see the correct answers and explanations. Most questions will include an explanation with the answer. Please take the time to read the explanations accompanying the answers to your questions. Doing so will give you a better overall understanding of the topic.

It is important to keep challenging yourself and practise your revision resources. Taking multiple attempts at our quizzes can help solidify the concept in your mind and increase the chances of achieving your desired score. You can even cheat a little😉 by reading the relevant paragraphs above if you are struggling with a question. In the end, you should be able to answer all the questions without referring to the notes above.

All our revision materials are designed to be easy to use and motivate you to practice, so don't give up! All the best!