In the previous Chapter, we talked about gas molecules moving around in a container. In solids, molecules are mostly fixed at their positions. But, each solid molecule vibrates hundreds of billions of times every second! Vibration is very different from normal motion because the object follows the same path repeatedly. We shall discuss such motion in this Chapter.

We start off learning about periodic motion, and when a periodic motion is called an Oscillation. We then discuss Displacement during an Oscillation, and how to mathematically represent Simple Harmonic Motion. We also explain what we mean by Time Period, Amplitude, Frequency, etc.