Angular velocity

Angular velocity is the rate of change of angular position with time. It is a signed scalar for planar motion and an axial vector in three dimensions.

Angular displacement: The change in angular position between two points in time. Angular velocity is the time rate of this change.
Angular position: An angle specifying an object's orientation or location around a chosen axis. Its change supplies the quantity whose time rate defines angular velocity.
Rigid body rotation: The motion of an object whose internal distances remain constant as it rotates. A rigid body's angular velocity characterizes its instantaneous rotation.
Angular speed: The nonnegative magnitude of angular velocity, without its direction or sign. It gives rotational rate alone, while angular velocity also encodes direction.
Radians per second: The SI unit of angular velocity, equal to one radian of rotation per second. This unit expresses angular displacement divided by elapsed time.
Radian: The angle subtended at a circle's center by an arc equal in length to its radius. Radians make the relation between angular and tangential speed direct.
Centripetal acceleration: The inward acceleration required for an object to follow a curved path. In uniform circular motion its magnitude depends on angular speed squared.
Frequency: The number of repeated cycles completed per unit time. Frequency counts rotations per time, whereas angular velocity measures angle per time.
Angular acceleration: The rate at which angular velocity changes with time. It describes how angular velocity varies during rotational motion.
Time: A dimension used to order events and measure their duration. Angular velocity is defined by angular change per unit time.

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