A rigid body may be defined as a body in which the relative positions of any two particles do not change under the action of forces means the distance between two points/particles remain same before and after applying external forces. A body which does not deform under the influence of forces is known as a rigid body.. The shearing force at any section of a beam is the algebraic sum of the lateral components of the forces acting on either side of the section. Where <b>forces</b> are neither in the lateral or axial direction they must be resolved in the usual way and only the lateral components are used to calculate the shear <b>force</b>. "/>A system of forces acting on a rigid body is equivalent to a force at