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…
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…
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…
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…
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…
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…
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…
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…