Iruni Kalupahana, JadeTimes Staff
I. Kalupahana is a Jadetimes news reporter covering Technollogy
What is Air?
Air is an invisible substance that surrounds us and has weight. It is made up of molecules that are always in motion, creating air pressure as they move. The movement of air generates force, which is why things like kites, balloons, and airplanes can fly. Air is a mixture of gases like oxygen, nitrogen, and carbon dioxide. All flying objects, whether birds, balloons, or planes, rely on air for lift and movement.
In 1640, scientist Evangelista Torricelli made an important discovery air has weight. By experimenting with mercury, he noticed that air exerted pressure on the liquid, which helped prove that air has mass. This discovery set the foundation for future innovations, including the idea of flight. In the late 1600s, Francesco Lana imagined an airship that would float using the principle of air's weight, although it was never built.
How Airplanes Fly?
Airplanes use the principles of aerodynamics to stay in the air. The wings of an airplane are specially designed to have an airfoil shape, with the top part of the wing curved and the bottom flatter. This shape causes air to travel faster over the top of the wing and slower underneath it.
According to Bernoulli’s principle, the faster moving air over the top of the wing creates lower pressure than the slower air beneath the wing, creating a lift force that pushes the airplane upward. This phenomenon is why airplanes can overcome gravity and stay airborne. The balance of lift, drag, thrust, and weight determines how the airplane moves through the air and maintains altitude.
Newton's Laws of Motion and Their Role in Flight
Newton’s three laws of motion are fundamental to understanding how airplanes fly and why they behave the way they do:
Inertia – An object will not move unless acted upon by an external force, and it will continue moving at a constant speed unless another force changes its motion. This explains why a plane must use thrust to overcome inertia and get off the ground.
Force and Acceleration – The second law states that the force applied to an object results in an acceleration that is proportional to the mass of the object. When more thrust is applied to an airplane, it accelerates faster, allowing it to take off or reach higher speeds in the air.
Action and Reaction – Newton’s third law explains how airplanes generate thrust and lift. The engines push air backward (action), and in return, the airplane moves forward (reaction). Similarly, the wings push air downward to create lift, and in return, the airplane rises.
The four main forces acting on an airplane lift, drag, weight, and thrust must be balanced for stable flight. If any one of these forces becomes stronger than the others, the plane will either climb, descend, or accelerate.
Controlling the Flight of an Airplane
Pilots control an airplane’s movements through careful manipulation of the aircraft’s control surfaces. The aileron controls the roll, tilting the wings left or right to turn the plane. The elevator at the tail adjusts the pitch, raising or lowering the nose to control altitude. The rudder on the tail is used to control yaw, or the plane’s turning left or right around its vertical axis. Pilots also control the throttle to manage engine power. Increasing power boosts the plane’s speed, while reducing power slows it down.
The combination of these controls allows the pilot to navigate the plane, keep it stable, and make smooth turns and changes in altitude. For example, when a pilot needs to climb, they pull back on the control yoke to raise the elevators and increase lift. If the plane needs to descend, the pilot pushes forward on the control yoke, lowering the elevators and reducing lift.
Supersonic Speed and Sonic Booms
When an airplane exceeds the speed of sound, it enters the supersonic range, traveling faster than 760 mph (Mach 1). As the plane moves at these high speeds, it compresses air molecules in front of it, creating a shockwave. This shockwave forms as a result of the rapid movement and compression of air, causing a dramatic increase in pressure ahead of the plane. When the plane breaks through this barrier, it creates a sonic boom, a loud sound that results from the sudden change in air pressure.
Supersonic flight is significant for military and commercial aviation, with planes like the Concorde able to fly at speeds of Mach 2 (twice the speed of sound). However, the noise from a sonic boom limits the use of supersonic aircraft for commercial travel over populated areas.
