A movement is
called
periodic when the values of the
magnitudes that describe the movement repeat themselves at regular time
intervals.
A periodic movement is an oscillation
if the trajectory is covered both ways, that is, if the
moving body goes back and forth.
An oscillation is a vibration if its
trajectory is a straight line and the origin is at the centre of the
trajectory.
A movement is HARMONIC when it is a
vibration in which the position, speed and acceleration
can be described using sine and cosine functions.
The simplest of all harmonic movements is the Simple Harmonic Motion,
which we will refer to from now on.
The SIMPLE HARMONIC
MOTION is a movement in which the
position of the moving body is given by a function of
the following kind: