Centrifugal

Centrifugal describes effects associated with rotation around a center, especially outward-directed effects observed in rotating systems. In physics, centrifugal force refers to an apparent force that seems to push objects away from the axis when analyzed from a rotating non-inertial reference frame. In an inertial frame, the outward tendency is explained by inertia, while the inward requirement to keep the motion is supplied by centripetal force.

For an object of mass m moving in a circle of radius r with angular speed ω, the centripetal acceleration is a_c = ω^2 r = v^2 / r, where v = ω r. The corresponding centrifugal force in the rotating frame is F_cf = m a_c = m ω^2 r = m v^2 / r. Centrifugal and centripetal descriptions describe the same motion from different frames of reference.

Centrifugal effects are exploited in devices such as centrifuges, which separate mixtures by density using rotation; centrifugal pumps, which impart energy to fluids through an impeller, producing outward flow; and centrifugal clutches or separators used in engineering applications.

The term is also used more generally to refer to outward directions away from the center in rotating systems, such as centrifugal forces in astrophysical disks or planetary rings, though precise force descriptions depend on the chosen frame of reference.