Invention Template

The Forces at Work

A general explanation of the forces affecting flight

What forces act on an airplane?

Credit to mansfieldct.org for the picture

The forces at work that affect how the airplane flies and what it takes for the airplane to go up are lift, drag, weight, and thrust. Combined, these forces present a host of problems that a designer of airplanes has to beat to enable the aircraft to take flight.

Weight

The weight of the aircraft is the constant force pulling the aircraft or object towards the earth, this gravitational forces generally known as the acceleration due to gravity multiplied with the mass of the vehicle determines the force that pulls the aircraft down. For the aircraft to defy gravity in a sense of the word and rise into the skies, the airplane needs to have a greater lift force compared to the force on the aircraft exerted by gravity.

Lift

Lift is the force that causes the plane to take to the skies, as discussed in the last paragraph about weight, once the lift force exceeds the weight the airplane will ascend. One of the main factors affecting lift would be the airfoil of the airplane, which is basically the shape of the wings cross section that gives a favorable lift to drag ration, allowing the plane to be more efficient in creating an upward force from its forward force.

Picture of an Airfoil courtesy of skybrary.aero

Thrust

Without thrust the plane wouldn't be able to move forward, and without the forward force there would be no lifting force levied from the wings to help the plane ascend. The thrust force is generated from the propulsion system, such as a propeller or jet engine.

Drag

Drag is the force opposing the forward motion of the aircraft caused by wind resistance levied from air pressing and flowing around bodies such as the wings. This force in particular is extremely important in slowing the plane down as intends to land on a runway, the methods used to create or dissipate drag are discussed in the next section about the steering of airplanes.