The 4 Forces of Flight
by: Annalise Sanderson
Lift is the force that holds the airplane in the air.Lift is generated by every part of the airplane , but most of the lift on a normal airplane is generated by the wing.Lift is a mechanical earodynamic force produced by the motion of the airplane through the air.
- Weight is the force of gravity. It acts in a downward direction—toward the center of the Earth.The force of gravity exerted on one object by another is directly proportional to the product of those objects' masses and inversely proportional to the square of the distance between them.
- Thrust is the force that propels a flying machine in the direction of motion. Engines produce thrust.Thrust is a reaction force described quantitatively by Newton's second and third laws. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction on that system.
- Drag is the force that acts opposite to the direction of motion. Drag is caused by friction and differences in air pressure.The phrase parasitic drag is mainly used in aerodynamics, since for lifting wings drag is in general small compared to lift.Drag depends on the properties of the fluid and on the size, shape, and speed of the object.