Excerpt from The Elements of Statics and Dynamics, Vol. 1 The science which treats of the action of force on bodies in motion is called Dynamics. In the more modern system of nomenclature which is gradually gaining general acceptance, the science which treats of the action of force on bodies is called Dynamics, and it has two subdivisions, Statics and Kinetics, treating of the action of forces on bodies which are at rest and in motion respectively.