Short note on general plane motion physics
Answers
A rigid body executes plane motion when all parts of the body move in parallel planes. For convenience, we generally consider the plane of motion to be the plane which contains the mass center, and we treat the body as a thin slab whose motion is confined to the plane of the slab. The plane motion of a rigid body may be divided into several categories.
∙ Translation is defined as any motion in which every line in the body remains parallel to its original position at all times. In translation there is no rotation of any line in the body. In rectilinear translation, all points in the body move in parallel straight lines. In curvilinear translation, all points move on congruent curves.
∙ Rotation about a fixed axis is the angular motion about the axis. It follows that all particles in a rigid body move in circular paths about the axis of rotation, and all lines in the body which are perpendicular to the axis of rotation rotate through the same angle in the same time.
∙ General plane motion of a rigid body is a combination of translation and rotation.