ENERGY

Without energy we would have no force. Each time a force pushes or pulls, this happens thanks to the energy. Nothing could happen in the whole Universe without the energy.

The potential energy represents that form of energy which you store when you lift a weight or when you pull a spring.

The chemical energy is stored in molecules. Food, petrol and any other kind of fuel are rich in chemical energy.

The kinetic energy is the energy that moving bodies have. The faster the body moves, the more kinetic energy it has.

Light is pure energy which travels at astonishing speed. Almost every kind of energy that we use comes from the Sun.

Heat is the energy caused by the agitation of atoms and molecules. The hotter a body is, the faster it's atoms agitate.

The electric energy is that form of energy that can be easily carried through wires, with almost no loss.

The black energy is a mysterious type of energy that makes the Universe to continuously expand.

The nuclear energy is produced when atoms separate or join together in the Sun, nuclear bombs or nuclear stations.

How does energy work?
Energy is like money. You can save it or you can spend it. The energy you store doesn't really help when it's stored, but it has potential. When you use it, it's like spending money, you get something in exchange, for example, light from a torch, but, finally, you have less energy stored.

How is energy measured?
Energy is measured in Joules. A Joule is approximately the energy you need to lift an apple at 1 meter high. A light bulb spends about 100 Joules per second, a person that runs spends about 1000, and a car about 100 000. A piece of pie contains around 2 000 000 Joules - enough to fuel a car for 20 seconds or to lift 2 million apples at 1 m high.

E = mc²
When an atomic bomb goes off, part of its matter is transformed in pure energy. Einstein's famous formula tells us exactly how much energy (E) is obtained. To find out the energy, in Joules, multiply the quantity of matter (m), in kilograms, with a colossal number: the square of the speed of light. Here's why an atomic bomb creates massive damage !