Pour a teaspoonful of salt into a glass of water.Now stir it and watch the salt slowly disappear from sight.It is dissolving in the water.How do you know the salt is still there? Try tasting a drop of the water.Gases also…
When you pump up your bicycle tires or football, you are making use of compressed air. Inside a bicycle pump is a small device called a valve. A valve allows a gas or a liquid to pass through it in…
Blow up a balloon and then let it go. The force of the high-pressure air coming out of the neck makes the balloon rush aimlessly in all directions. This type of force pushing the balloon forwards is called thrust. It…
Look out of your window. Is the air moving? It is probably moving enough to make the branches on the trees sway slightly. The weight of this air pressing down all around the earth produces air pressure. If you live…
The weight of this air pressing down all around the earth produces air pressure. It is probably moving enough to make the branches on the trees sway slightly.
What is an airfoil? When an airfoil moves through the air, it produces lift because the force of the air pushing down on its top surface is less than the force of the air from below. The uneven pressure causes…
How to Make a Pinwheel? You will need: a pencil a ruler a piece of thin cardboard, 4 in x 4 in (10 cm x 10 cm) a pin scissors a small bead a stick, about 10 in long (25…
About one-fifth of the air is oxygen. Human beings and other animals would not be able to survive without oxygen. When we breathe, our lungs take the oxygen we need from the air. Another very important gas in the air…
Have you ever wondered what everything in the world is made from? The answer is matter.Matter is anything that takes up space and has mass.There are millions of different things in the world, but there are just three different forms of…
What are Tires Made out of? Think of all the different things that can be made from rubber.There are gloves, rubber bands, boots and shoes, fan belts for cars, inflatable boats, bottle stoppers, balls, tires, and foam mattresses.The rubber used…