Energy: the ability to do work
Everything that happens needs energy: a ball rolling, a lamp shining, a child running to school. Energy is the ability to do work. We cannot see energy itself, but we can see what it does. When we see movement, feel heat, see light or hear a sound, we know energy is at work. Energy comes in different forms: motion, heat, light, sound, electrical and chemical energy. Energy can be stored for later. Food stores chemical energy, and so does a battery. Energy can also change from one form to another. In a torch, the energy stored in the battery changes into light and a little heat. We cannot make new energy from nothing, and we cannot make it vanish: it only changes form or moves from place to place.
| Form of energy | Where we notice it |
|---|---|
| motion | a bus driving, a kicked ball |
| heat | a warm radiator, a hot tea glass |
| light | a lamp, the Sun |
| sound | a drum, a bell |
| chemical (stored) | food, batteries, gas in a cylinder |
Energy detectives. With a grown-up, walk round your home and find five things that use energy. For each one write the form of energy you notice (movement, heat, light or sound) in a table: Thing, What I see, feel or hear, Form of energy. Example: ceiling fan, air moves, motion.