IB Sports, exercise and health science B.2.2.3 Buoyancy, Drag, and Lift Effects on Objects Moving Through Fluids Key Definitions

When fluid velocity increases, pressure decreases, and vice versa. This principle explains how lift is generated in sports.

Buoyancy is the upward force exerted by a fluid (air or water) that opposes the weight of an object submerged in it.

Drag is the resistive force that opposes the motion of an object through a fluid.

Form Drag is the drag caused by the separation of the boundary layer from a surface and the wake created by that separation

Lift is the force that acts at a right angle to the direction of motion through the air. Lift is created by differences in air pressure.

Surface drag is the resistance that occurs when an object moves through a fluid, such as air or water, due to friction between the object's surface and the fluid.

Wave Drag is a drag force acting on a body that is moving at the interface of two fluids.