Inertial force, any force invoked by an observer to maintain the validity of Isaac Newton’s second law of motion in a reference frame that is rotating or otherwise accelerating at a constant rate. For specific inertial forces, see centrifugal force; Cor
can be obtained to a satisfactory degree of accuracy by assuming that an Earth-based reference frame is an inertial one, there are some applications in which the rotation of the Earth cannot be neglected; among these is the operation of agyroscopic compass. (Seecentrifugal force;Coriolis force....