An Introduction to Flight
Airplanes are arguably one of man’s greatest inventions. Men have looked to the sky and wondered if one day they could fly like birds and other creatures that so effortlessly soared above them. This curiosity has led to many mishaps in the realm of flight, but, ultimately, airplanes were invented, and people were able to use them to fly. Since their invention, planes have been a fascination to many in addition to a popular and useful mode of transportation. How do these mechanisms fly, though? And how do they stay in the air? This can be explained by two principles of physics, thrust and lift. The two work together in order to keep planes in the air and make them fly.
Lift is the main principle in flight. Newton’s third law of physics comes into play here, which states than for every action there is an equal and opposite reaction. The action and reaction here involves the amount of pressure the wing of an airplane puts on the air around it and the pressure the air puts on the wing when it pushes back. When an airplane is traveling, it pushes on the air around it in all directions. However, it pushes with less pressure up, and more pressure down. As a rule, equal pressure from the air will be exerted onto the wing, which means more pressure will exert itself on the wind from underneath, which results in the wing being lifted, and thus the plane being able to fly. A wing does this because of its design, which is flat on the bottom and curved on the top. The curve on the top creates an area of low pressure that makes lift possible.
Thrust is the second important principle that is taken into account when talking about how planes fly. Thrust is what propels the plane forward and also what gets the air to move around the wing. Air needs to move quickly over the wing in order for it to create lift, and this can only be done when the plane moves at high speeds. Depending on the plane in question, thrust could be created by a propeller or some kind of jet engine. Either way, when there is enough thrust to bring the plane to a speed that makes the air move over the wings at just the right speed, lift is able to occur and the plane flies. The plane must keep at the same speed or a higher one in order to continue to fly.