Saturday, May 12, 2007 4:58:10 PM
serfis, simple harmonic motion occurs when the acceleration of a body is always towards its natural "rest" position, and when the acceleration is directly proportional to the distance it is away from this position so a = k(-x) where a is a constant. The relationship crops up so often everywhere in nature that they started using the term SHM. (I am assuming that whatever the relationship between height and density of air, the amplitude of cloud oscillation is small enough compared to the height above the ground, that the relationship is approximately linear over that region, giving SHM.)