Simple Harmonic Motion
Definition of Simple Harmonic Motion
Simple Harmonic Motion in physics or SHM is
defined as oscillating motion of an object about an fixed point
such that the acceleration (a) of the object is:
- proportional to the displacement (x) from the fixed
point,
- always directed towards the fixed point
The definition of Simple Harmonic Motion (SHM) can be
summarized in the Simple Harmonic Motion equation
below.
Formula for Simple Harmonic Motion

where:
 |
= acceleration (unit is ms
-2) |
 |
= displacement (unit is
m) |
 |
= angular frequency
(unit = rad s -1) |
In another word, Simple Harmonic Motion
(SHM) is a form of periodic motion in which a point or body
oscillates along a line about a central point in such as way
that it ranges an equal distance on either side of the central
point and that its acceleration towards the central point is
always proportional to its distance from it.
Visualizing Simple Harmonic Motion in
Physics
One way to visualize Simple Harmonic Motion
is to imagine a point rotating around a circle of radius r at a
constant angular velocity . If the distance from the center of the circle
to the projection of this point on a vertical diameter is
y at time t, this projection of he point will move about
the center of the circle with simple harmonic motion. A
graph of y against t will be a sine wave, whose equation
is:

|