Rotation

• Date: 1555

Definitions

• 1 a (1) : the action or process of rotating on or as if on an axis or center (2) : the act or an instance of rotating something

b : one complete turn : the angular displacement required to return a rotating body or figure to its original orientation

• 2 a : return or succession in a series <rotation of the seasons>

b : crop rotation

• 3 : the turning of a body part about its long axis as if on a pivot
• 4 : a game of pool in which all 15 object balls are shot in numerical order
• 5 : the series of pitchers on a baseball team who regularly start successive games in turn

Description

A rotation is a movement of an object in a circular motion. A two-dimensional object rotates around a center (or point) of rotation. A three-dimensional object rotates around an imaginary line called an axis. If the axis of rotation is within the body, the body is said to rotate upon itself, or spin—which implies relative speed and perhaps free-movement with angular momentum. A circular motion about an external point, e.g. the Earth about the Sun, is called an orbit or more properly an orbital revolution.

See also

• Spin