Drag is a force acting opposite to the direction of motion of an object moving through a fluid, such as air. Drag is the aerodynamic force that opposes the forward motion of an aircraft. It is caused by the frictional resistance of the air against the aircraft’s surfaces, as well as the pressure differences created by the airflow around the aircraft. The formula to calculate Drag as follows:
Where:
- is the drag force (in newtons or pounds),
- is the drag coefficient (a dimensionless quantity),
- is the air density (in kilograms per cubic meter or slugs per cubic foot),
- is the velocity of the aircraft relative to the air (in meters per second or feet per second),
- is the reference area (such as the wing area) (in square meters or square feet)