| any force that is postulated to account for apparent deviations from Newton's laws of motion appearing in an accelerated reference system. |
| fictitious force n. See pseudo force. |
| pseudo force n. The physically apparent but nonexistent force needed by an observer in a noninertial frame to make Newton's laws of motion hold true. The centrifugal force is a pseudo force. Also called fictitious force. |
fictitious 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; Coriolis force; d'Alembert's principle.
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