Kinetics of Particles and Rigid Bodies
The mechanics of rigid bodies may be divided into statics and dynamics. Dynamics is further divided into kinematics and kinetics. Kinematics is concerned with rates of change of geometrical quantities in a moving system; it does not involve the concept of force. Kinetics treats the causes of motion and the nature of motion that results from specified forces. The relationships among position, velocity and acceleration of a moving body, such as a thrown ball, are defined by kinematics. The relationship between the forces that act on the ball and the motion of the ball involves kinetics.
NEWTON'S LAW OF GRAVITATIONAL ATTRACTION
Any two bodies whose dimensions are negligible compared to the ...