Rigid body
lastmod 2020-09-20created 2020-09-202 edits
In physics, a rigid body is an object whose shape is fixed and does not change. A rigid body does not deform in shape or size even when an external force is applied. In the real world, every object can deform slightly in shape or size as external forces are applied, so none is truly a rigid body, but an object is sometimes assumed to be a rigid body if its deformation is small enough to be negligible. When analyzing the motion of an object, the object is usually assumed to be a rigid body.