Class 11

An example of the periodic motion is Earth's revolution. In this, the motion repeats itself after regular intervals of time. In oscillatory motion, the object moves back and forth about a mean position like a vibrating spring or pendulum. It is a type of periodic motion. Although, oscillatory motions are periodic, however, not vice versa. Oscillatory motion typically follows sinusoidal patterns and involves a restoring force.

In Simple Harmonic Motion (SHM), the restoring force is directly proportional to the displacement from the mean position. It is a periodic motion and acts in the opposite direction. SHM follows the equation, F=? kx, where k is the force constant and x is the displacement. Simple Harmonic Motion is characterized by constant frequency, sinusoidal oscillations, and energy interchange between potential and kinetic forms. Examples are the vibrating springs,  the motion of a pendulum (for small angles), and molecules in a lattice.