Periodic and Oscillatory Motions

Physics

definition

Periodic Motion

Periodic motion, motion repeated in equal intervals of time. Periodic motion is performed, for example, by a rocking chair, a bouncing ball, a vibrating tuning fork, a swing in motion, the Earth in its orbit around the Sun, and a water wave.

definition

Periodic Motion Graph

Periodic Motion Graph is as shown:

definition

Mathematical Condition of Simple Harmonic Motion

When the restoring force of any motion has equation of form:

Then fundamentally this equation represents simple harmonic motion.

example

how to identify periodic and non periodic motion

A motion that repeats itself at regular intervals of time is called periodic motion.
Example :  Explain whether Functions 1. and 2. are periodic or not?
1. we can write as
 =
 =
The periodic time of function is
So it is periodic motion.
2. The function decreases monotonically with increasing time and tends to zero as t approaches infinity and thus never repeats its value.
Hence it is non periodic motion.