5.2.2 Damping and Force Oscillation

Natural Frequency

The Natural frequency of an oscillating system is the frequency of the system when there is no external force or forces acting on it.

Damping, Force Oscillation and Resonance

Damping

1. Damping is the decrease of amplitude of an oscillating system.
2. An oscillating system experiences damping when its energy is losing to the surrounding as heat energy.
3. Usually, the frequency of the system remain unchanged.

(Displacement-time graph of a damped oscillation)

(Amplitude-time graph of a damped oscillation)

Type of Damping

Damping can be divided into:

1. internal damping , where an oscillating system loses energy to overcome frictional force or air resistance that act on it.
2. external damping , where an oscillating system loses energy due to the extension and compression of the molecules in the system.

Force Oscillation

1. In a damped oscillation, external force must be applied to the system to enable the oscillation to go on continuously.
2. Oscillation with the help of external force or forces is called a force oscillation.