How Does an Aircraft Fly?

How does an Airplane fly? Every day of our lives, we hear or see at least one type of aircraft sore above our heads. Most of us travel on one once a year to make a journey of over a hundred miles to another country in an hour or two on an airplane. But how can a standard 737 (which weighs roughly 50 kg per square meter) resist the force of gravity. How can it soar at 35,000 feet at a speed of 500 miles per hour. In this article I will talk about the science behind flying in heavier than air machines. There are two factors that prevent an airplane from flying. These are weight (preventing a plane from rising) and drag (preventing it from moving forward. For an airplane to fly, these factors must be equalled out be another two which are produced by the airplane. These are lift (created by the wings and other parts) and thrust (created by the engines. The following equations below must be obeyed to take off from the ground. - Drag < Thrust (to move forward) - Weight < Lift (to rise) Now let's look at each component individually. Drag is caused by friction with the air. As an airplane flies, its body brushes against the different air molecules creating friction. This slows the plane down. Thrust is the opposite of drag as it is used to propel a body forward. It is created using Newton's third law of motion. It states that when one force goes one way, a force of equal strength must go the other way. Hence thrust is created by huge engines pulling and pushing huge amounts of air out the back. Therefore, an equal force must go the other way. Weight is caused by gravity. The mass of an object depends upon what it is made up of and the weight of an object is this number in kilograms multiplied by the gravitational field strength of the Earth which is roughly 9.8 N/kg. Einstein proposed General Relatity in 1915 which states that a body curves Sapce-Time and this curvature pulls bodies into the object. This is known as gravity. We counter gravity by using lift. We generate lift by angling the the wings so that it pushes air down. Newton's third law comes in to play again here as the air is pushed down, another force must go up. IN other words, the plane rises. Of course, Lift doesn't have to be more than weight when its cruising as the pilot will want to remain level so the the lift will be equal the weight. So next time you are watching a plane cruise in to the sky, remember the physics behind this way of travelling that has been attempted many times for centuries that has now become a reality.