What is aerodynamics?
Aerodynamics is a concept to explain how an object move through the air. Everything that is moving on the earth reacts with aerodynamics. We can't know why airplanes fly without learning and knowing aerodynamics. I'm going to introduce basic information about aerodynamics which are lift, thrust, weight and drag. These four are called four forces.
![Picture](/uploads/2/5/0/7/25079019/9782568.jpg?1386088206)
Weight is a force which pulls down an object. This force is known as gravity. In a flight, there has to be a power that pushes opposite direction of gravity. It must overcome weight force to fly. The power that is opposite to weight is lift. There should be more lift than weight when objects are flying as I wrote already. For instance, hot balloons fly because the air inside is lighter than the air around the ballon. Drag is a force that makes an object stop. For examples, when you walk inside water. It would be harder to walk than walking on lands because there are more force of drag. Shape of an object can change drag. Round surface objects usually have less drag than the flat one because there would be more air hitting an object if the surface of it is flat. Opposite force of drag is called thrust. A force that is opposite to drag is thrust. It is a force to forward. For airplanes, thrust is usually created by jet engines or propellors.
Now I presume that you have a question, "how does airplane make its lift force?" because four forces do not explain about it. To answer this question, we need to know about the principle called BERNOULLI'S PRINCIPLE.