Rotation
|
|
Types of motionTranslationAll points in an object have equal displacement and velocity vectors; all points move parallel to each other. RotationAll points in an object (except a set of points that remain fixed; these form an axis) move in circular motion with different radii; the displacement and velocity vectors are different for different points. Translation + rotationTranslation and rotation can occur together: the points in the axis move in translational motion whilst all the other points rotate about the axis – eg, rolling motion. |
In rotation, all particles of an object go round in circular motion but there is a set of one or more particles (forming a fulcrum or an axis) which remain fixed.
Fulcrum
The point which remains fixed in rotational motion – eg, the tip of a top (a spinning toy).
Axis
The line formed by the points that remain stationary during rotational motion – eg, hinge of a door.
Rigid object
An extended object in which the relative locations of all particles of which the object is composed remain constant.