Oscillation is a measure of some repetitive variation, as a function of time. It can be measured with respect to a state of equilibrium. The most common and simplest example for oscillation is the motion of a simple pendulum.
The three types of simple harmonic motion in physics are:
- Free Oscillation
- Forced Oscillation
- Damped Oscillations
Free Oscillation: The amplitude and time period remain constant without any influence of external factors. When the system has zero damping, the amplitude remains constant provided, this theory is possible in cases where damping always occurs.
In order to overcome external forces like air resistance or friction, the reduction in amplitude (energy loss of a system) is referred to as damping. As a result, the amplitude, frequency, and energy all remain constant.
Forced Oscillation: When an external periodic force influences a body's oscillation, then it is called forced oscillation. Here, damping occurs in the amplitude of oscillation but remains constant with the help of the external energy supplied by the system. For example, constantly pushing a swing so that its oscillation doesn't reduce.
Damped Oscillation: The reduction of the amplitude of an object with respect to time, such type of oscillations are known as damped oscillations. The energy of a system decreases with the decrease in amplitude. There are two types of damping: Natural Damping and Artificial Damping.
Resonance: It is the phenomenon wherein an external vibrating system causes the oscillation of another system with a higher amplitude at a particular frequency. The frequency at that particular resonance level is known as a resonant frequency.
For instance, when tuning a guitar with the help of another guitar, the resonant frequency can be observed. In this case, the amplitude of the vibration of the string is the highest. The reason for large amplitude oscillations generated at that resonant frequencies are as a result of vibrational energy that is accumulated in the system.