In fact the cork is undergoing simple harmonic motion and the horizontal peak to peak distance in the is the period, \(T\) of the wave (just like the peak to peak distance of a time graph of harmonic ...In fact the cork is undergoing simple harmonic motion and the horizontal peak to peak distance in the is the period, \(T\) of the wave (just like the peak to peak distance of a time graph of harmonic motion was the period).