A lumped system is one that can be decomposed into a finite number of compo nents, each with a finite number of inputs and outputs, and such that the values Of the outputs at every time are functions of the inputs, their derivatives, and their integralS at the same instant of time. Since the velocity of light and velocity of sound are finite' all physical objects with inputs and outputs at different places are not lumped. Nevertheless, the lumped system can provide a good approximation for a physical system.