Oscillatory Motion

Introduction 1

The periodic motion performed by a body or a material point about its equilibrium position is called mechanical oscillation. This oscillation often occur in everyday life. For example the oscillations of a clock pendulum, the vibrations of a string, the oscillations of a glider, all these are frequently encountered mechanical oscillations.

Introduction 2

Beside the mechanical oscillations, also exist and oscillations of the electric and magnetic fields. When we speak, the molecules of air oscillate back and forth along the direction of sound’s propagation, and when the electromagnetic waves are emitted, the oscillating quantities are the electric and magnetic vectors of the electromagnetic field.

Introduction 3

If the deviation from the equilibrium position is very small and if the friction force can be neglected then the mechanical oscillations are called harmonic or free oscillations otherwise the oscillations are called anharmonic oscillations.

Introduction 4

The oscillations can be also classified in free oscillations, damped oscillations, forced oscillations, linear or nonlinear oscillations, conservative or dissipative oscillations, auto-oscillations and parametric oscillations. The auto-oscillations, and parametric oscillations are particular cases of the forced oscillations.

Harmonic Oscillations 1

Let us consider a system consisting of a round small ball at rest inside of a perfectly rounded smooth cup. If the ball is slightly deflected from its equilibrium position and is released with then under the action of gravity force, the ball will start to oscillate to the left and to the right of the position of equilibrium.