 Kinematics is a branch of classical mechanics that describes the motion of points, bodies objects and systems of bodies groups of objects without considering the forces that caused the motion. Kinematics, as a field of study, is often referred to as the geometry of motion and is occasionally seen as a branch of mathematics. The kinematics problem begins by describing the geometry of the system and declaring the initial conditions of any known values of position, velocity and slash or acceleration of points within a system. Then, using arguments from geometry, the position, velocity and acceleration of any unknown parts of the system can be determined. The study of how forces act on bodies falls within kinetics, not kinematics. For further details, see analytical dynamics. Kinematics is used in astrophysics to describe the motion of celestial bodies and collections of such bodies. In mechanical engineering, robotics, and biomechanics kinematics is used to describe the motion of systems composed of joint parts multi-link systems such as an engine, the robotic arm or the human skeleton. Geometric transformations, also called rigid transformations, are used to describe the movement of components in a mechanical system, simplifying the derivation of the equations of motion. They are also central to dynamic analysis. Kinematic analysis is the process of measuring the kinematic quantities used to describe motion. In engineering, for instance, kinematic analysis may be used to find the range of movement for a given mechanism, and working in reverse, using kinematic synthesis to design a mechanism for a desired range of motion.In addition, kinematic supplies algebraic geometry to the study of the mechanical advantage of the mechanical system or mechanism.