Oscillations

Introduction:

Any motion or event that repeats itself at regular intervals are said to be periodic. In some periodic motions a body moves to and fro motion along a given path between two extreme positions.

                                

Examples: * The vibration of a guitar string or a speaker cone.                                                  * The motion of a piston in an engine.                                                                        * The vibrations of the atoms in a solid.

Such as periodic motions are examples of oscillations. In general, an oscillation is a periodic fluctuation in the value of a physical quantity above and below some central equilibrium value.

    Periodic and Oscillatory motions:

The motion which repeats at A regular interval of time is called periodic motion. The periodic motion in which a body moves to and fro about a fixed point is called oscillatory motion.

Note:  All periodic motions need not be oscillatory motion. But all oscillatory motions are periodic motion.

         1. An insect climbs up a ramp and falls down it comes back to the initial point and repeats the process identically. A graph of its height above the ground versus time.

Graph:

*                 2. If a person climbs up a step, comes down, and repeats the process, a graph between is the height above the ground versus time

Simple Harmonic Motion (SHM):

            The to and fro motion of a particle along a straight line about a fixed point is said to be a Simple Harmonic Motion. If

*        When the direction of its acceleration always towards the fixed point.

*        The magnitude of the acceleration is directly proportional to its displacement from that fixed point.

A similar way of to and fro motion diagram