kinetics /kinet″iks/ [Gk, kinesis, motion + L, icus, like] , 1. the study of the forces that produce, arrest, or modify the motions of the body. Newton’s first and third laws of motion are especially applicable to kinetics. These two laws apply to the forces produced by muscles that act on joints. The reaction forces of the muscles contribute to equilibrium and the motion of the body. Compare kinematics. See also Newton’s laws. 2. the study of the rate of chemical and biochemical reactions as in chemical kinetics and enzyme kinetics. It may also refer to the fate of pharmaceuticals upon administration to an organism in terms of absorption, distribution, metabolism, and excretion. See also pharmacokinetics.
