Generation of simple harmonic motions

Simple harmonic motion is examined from the viewpoint of how such motion can be generated. It is shown that a family of plane curves including circles as its subfamily generate simple harmonic motions by projection. The idea of dynamic force constants is introduced. Employing such an idea, one may conclude that any force field that generates a simple harmonic motion is equivalent to the force field obeying Hooke’s law with the force constant replaced by the appropriately generalized dynamic force constant.