Mechanics: Dynamics

Dynamics is the study of rigid bodies in motion due the action of external forces as stated in Newton's Laws and is concerned with the equilibrium state of the rigid body in motion under the action of forces as stated in Newton's Second Laws. Therefore dynamics mechanics only deals with dynamics problems where rigid bodys are always in motion. The study of the dynamic equilibrium state of rigid bodies can be divided into kinematics and kinetics.

Kinematic

Kinematics focuses only on the geometry of the motion of a rigid body under uniform or variable forces to which only the effects on the motion are considered, i.e. acceleration, velocity and displacement. Kinematic is therefore the study of the relationship of displacement, velocity, and acceleration with respect to time as mtion is always in reference to time. 

Kinetic

Kinetic is the study of the interaction of a rigid body, the motion of the rigid body and forces acting on the rigid body. Kinetic is therefore the study of the relationship of the motion of a rigid body due to applied forces, or the applied force applied to the rigid body to cause the motion.