Vibrations in Action!

The physics behind vibrations is actually rather fascinating, but difficult to comprehend if not previously studied. To start, think waves; vibrations can be visualized as waves on a graph. One wave is called a period and can be calculated by the total time dived by the total number of waves. The total number of waves divided by time is how we calculate frequency. Now, before an object is vibrating it is in a state of equilibrium and the line on our graph is constant because no forces are acting upon that object. When force is applied to the object, the graph is going to change. In the case of vibrations the graph repeats itself, it oscillates. Essentially, the energy given to a vibrating object cycles through a particular motion until the energy disipates and the motion stops. In a perfect world where no outside forces can affect vibration, an oscilating object would continue forever due to Newton's law of intertia. Unfortunately, we do not live in a perfect world, and outside forces cause the energy within a vibration to translate and transform in ways that no longer work in accordance to the vibration.

http://dev.physicslab.org/Document.aspx?doctype=3&filename=WavesSound_VibrationGraphs.xml