What is Energy
Test your knowledge on Energy in the Energy Quiz after you have read this information.
There are lots of fun energy activities to do.
Energy is all around us and it is a part of us. It is everywhere!
Our universe is made from energy and it is fundamental to the existence of everything!
It exists as light, heat, sound, mass, moving objects, gravity, fuel, chemicals, and electricity. We use many of these different types of energy to enhance our lives every day.
Food is the main source of energy that fuels our bodies, helping us to grow, run, talk and think. It is one of our most important sources of energy.
Electrical energy is used to power most things in our modern society including computers, televisions, fridges and freezers, vacuum cleaners, toasters, stereos, lights etc. It is also very important for our industries, as it is the source of power for manufacturing as well as for refining and processing minerals.
Fossil fuel energy powers our cars, buses, trucks, boats and aeroplanes, to help move us around and trade goods with others.
Energy helps us to work, go places, communicate with others and live more comfortably.
The concept of energy is one of the most important in science. It is also a concept that is difficult to define in a simple and accurate way.
Think about what it is like when you say you have no energy. You don't feel you can run or play or do much at all. The common definition of energy is 'the ability to do work'.
Work = Force x Distance.
The energy of an object is how much work the object can do on some other object.
Although this definition is not readily obvious for all types of energy, it helps us realise the important connection between energy and work.
Laws of conservation of energy
The law of conservation of energy states that energy cannot be created or destroyed. It can only be transformed from one form to another as well as transferred from one body to another but the total energy remains the same.
Units for Measuring Energy and Power
The standard unit of measurement for energy is the Joule (J). One 1J = 1N.m (Newton Metre).
Power is measured in joules per second, and this is called the watt (W) and is defined as the rate at which work is done. 1 Watt = 1 Joule / Second. It can be the rate at which energy is consumed or power is generated. We know that the watt is used to measure the rate that an electric light bulb changes electric energy into light energy. We often hear the terms kilowatts and megawatts. One kilowatt (kW) is one thousand watts and one megawatt (MW) is one million watts.