Lift (force)

When a <a href="/facts/Fluid/tMQ46Tmz">fluid</a> flows around an object, the fluid exerts a <a href="/facts/Force/533Q1uzq">force</a> on the object. Lift is the <a href="/facts/Euclidean_vector/bCLrdksy">component</a> of this force that is perpendicular to the oncoming flow direction. It contrasts with the <a href="/facts/Drag_(physics)/vdl4jF7I">drag</a> force, which is the component of the force parallel to the flow direction. Lift conventionally acts in an upward direction in order to counter the force of <a href="/facts/Gravity/bqAN7DdQ">gravity</a>, but it is defined to act perpendicular to the flow and therefore can act in any direction.
If the surrounding fluid is air, the force is called an <a href="/facts/Aerodynamic_force/V9C98uHk">aerodynamic force</a>. In water or any other liquid, it is called a <a href="/facts/Fluid_dynamics/y7uzSCfg">hydrodynamic force</a>.
Dynamic lift is distinguished from other kinds of lift in fluids. <a href="/facts/Aerostatics/KeVyNE4A">Aerostatic</a> lift or <a href="/facts/Buoyancy/9dIQwlrh">buoyancy</a>, in which an internal fluid is lighter than the surrounding fluid, does not require movement and is used by balloons, blimps, dirigibles, boats, and submarines. <a href="/facts/Planing_(boat)/bfpdkCwI">Planing lift</a>, in which only the lower portion of the body is immersed in a liquid flow, is used by motorboats, surfboards, windsurfers, sailboats, and water-skis.

Lift (force) open-in-new

Lift (force)