What is energy?
Energy is what makes things work, move and change. You use energy to run and play, a car uses energy to move, and a lamp uses energy to give light. Energy comes in different forms and from different sources.
Key idea
The Sun is the main source of energy for the Earth. Energy can appear in many forms, such as light, heat, sound and electricity.
Forms of energy
Here are some common forms of energy you meet every day:
- Light energy — from the Sun, a lamp or a torch.
- Heat energy — from the Sun, a fire or a stove.
- Sound energy — from a drum, a radio or your voice.
- Electrical energy — from a battery or a wall socket.
Energy can also change from one form into another. This is very useful, because it lets our machines and bodies do many different jobs.
Example
A television changes electrical energy into light energy (the picture) and sound energy (the sound you hear).
Remember
- The Sun is the main source of energy on Earth.
- Food, batteries and fuel are also useful sources of energy.