π§ͺ Science β‘ Energy and electricity
Energy
π In short
Energy is the ability to do work or make a change. We need energy to run and play, a car needs it to move, a lamp to shine and an oven to cook. Energy doesn't disappear but changes from one form to another.
π€© Did you know?
- A train going 80 kilometers an hour has four times as much movement energy as a train going half that speed.
- Energy is measured in a unit called the joule.
- Renewable energy like sunshine and wind never runs out.
- Your brain needs lots of energy to think!
π Find out more
π Forms of energy
Energy has many forms: movement energy in a rolling ball, heat energy in fire, light energy from the sun, electrical energy, sound energy, and energy stored in food and fuel.
π Energy changes
When you eat, your body turns food energy into movement and heat. In a lamp, electrical energy turns into light and heat. In solar panels, sunlight turns into electricity.
π‘ The Sun, mother of energy
Most of the energy on Earth comes from the Sun: plants store its energy, animals eat plants, and oil and coal were made by ancient living things that lived on the Sun's energy.
π― Save energy
Switch off lights and devices you're not using, close the fridge door quickly, and cycle or walk, and you'll save energy and protect our environment.
𧩠Test yourself
1 Where does most of the energy on Earth come from?
2 What happens to energy?
3 A train going ?? kilometers an hour has four times as much movement energy as a train going half that speed.
4 Which picture shows βEnergyβ?
π§ͺ Discover more
π· Picture sources: Wikimedia Commons
- Colin Β· CC BY-SA 3.0
