Statics, Systems of Forces, Hydrostatics

In Kinematics, the geometry of motion is studied without consideration of the sources of the deformation or acceleration. From observations, it is concluded that the driving agent of any change of the state of motion is a force. Thus, the notion of force is at first heuristically introduced, and later physical definitions of force are given by Newton’s law or through the notion of power or work (and energy). Another definition of force is given by the flux of a potential field, the gradient, which is used also in nonmechanical fields like thermodynamics, chemistry, and electrical sciences for the driving agent. In this section, the geometry of forces is studied, eg by considering the reduction of a system of forces and the equilibrium state; thereby, the occurrence of a double force with moment is detected. Theory and applications presented in this chapter are basic to the field of Statics and, hence, for the equilibrium of balanced forces acting on bodies at rest.