Category What is

Have you ever taken a spoon out of a mug of hot cocoa or tea or some other hot drink? Did you find that the spoon was too hot to hold, so that you had to drop it? Did you…

Do you know that you are working when you are playing? To a scientist, work is any kind of action that uses energy. Energy is needed to do all types of work—for example, to throw a ball into the air…

Every form of energy can change into another form of energy.Coal is a fuel that contains stored chemical energy. When coal burns, the chemical energy inside it changes into heat energy.Energy may change in form, but it can’t be made…

Have you ever heard a jet airplane when it is getting ready to take off? The noise that the plane makes is sometimes so loud that you cannot hear any other noise.Sound is a type of energy. Sounds are produced when…

“On your marks! Get set! Go! ” These are the orders the starter shouts when you take part in a running race. When you are running, your body has a lot of kinetic energy, the energy of movement. When you…

Have you ever been to a display of chemical energy?You probably have, but you called it something else. At a display of chemical energy, there are usually many different colored lights and a lot of noise.Rockets shoot up into the…

How do you keep cool in your house? What sort of light do you use at night? What appliances do you have in your home? Anything that gives you heat or light uses energy. Household appliances use energy. In your…

The world is full of movement.Trees move in the wind.Aircraft fly in the air.Ships sail on the sea.People and animals move around.None of these things can move without energy. Living things and machines need energy in order to work. Where…

Who invented the airplane? The thought of flying like a bird, is among the oldest of human dreams. One of the most famous legends of the ancient Greeks, talks about Icarus, who glued wings with wax to himself and soared…

Have you ever wondered who invented the parachute? Imagine if you find yourself into an empty space at the height of 4-5 miles above the Earth, and yet you have landed on the ground as if you jumped from fence…