Click here to purchase the entire book in PDF format. Simple Harmonic Motion Take a weight (a little one...) and hang it on the end of a Slinky which is attached to the ceiling and wait for it to stop bouncing. Measure the length of the Slinky. This length is determined by the weight and the strength of the Slinky. If you use a bigger weight, the Slinky will be longer - if the slinky is stronger, it will be better able to support the weight and therefore be shorter. This is the point where the ``system'' is at rest or stasis. Pull down on the weight a little bit and let go. The Slinky will pull the weight up to the stasis point and pass it. By the time the whole thing slows down, the weight will be too high and will want to come back down to the stasis point, which it will do, stopping at the point where we let it go in the first place (or almost anyway...) If we attached a pen to the weight and ran piece of paper along by it as it sat there bobbing up and down, the line it would draw a sinusoidal waveform. The picture the weight would draw is a graph of the vertical position of the weight (the y-axis) as it relates to time (the x-axis). If the graph is a perfect sinusoidal shape, then we call the system (the Slinky and the weight on the end) a simple harmonic oscillator.