Difference Between Oscillatory Motion and Periodic Motion

Oscillatory Motion vs Periodic Motion
 

Oscillatory and periodic motions are very abundant in nature and are, therefore, very important in many systems. Oscillatory motions are motions where an equilibrium point exists. Periodic motions are motions that repeat itself over time. Both of these motion types are widely applicable in fields like astronomy, cosmology, satellite technology, clock manufacturing, planetary motion, automobile engineering, machinery and various other fields. It is vital to have a proper understanding of these motions in order to excel in such fields. In this article, we are going to discuss what oscillatory motions and periodic motions are, their definitions, the similarities between oscillatory motion and periodic motion, their applications and finally the difference between oscillatory motion and periodic motion.

Periodic Motion

Periodic motions are defined as any type of motion that repeats itself over time. Periodic motions are abundant in nature. Motions such as planetary motion, the motion of moons around planets, the motion of orbital satellites, the motion of the blades of a fan, the rotation of an engine are some examples for periodic motions. Periodic motions can be classified into two main categories. First one is natural periodic motions, which occur in nature without any external force; the second type is artificial or man-made periodic motions. These motions are forced periodic motions such as diesel engines. Periodic motions can occur either in regular paths such as circles, ellipses or in irregular paths, which cannot be defined easily. Most of the periodic motions occurring in irregular paths are forced periodic motions.

Oscillatory Motion

Oscillatory motions are a type of periodic motion. An oscillatory motion is usually defined as a repetitive variation over time. The oscillatory motion can occur over a middle equilibrium point or between two states. A pendulum is a good example for an oscillatory motion. The oscillatory motions are mostly sinusoidal. An alternating current is also a good example for oscillatory motion. In the simple pendulum, the bob oscillates over the middle equilibrium point. In an alternating current, the electrons oscillate inside the closed circuit over an equilibrium point. There are three types of oscillatory motions. The first type is the un-damped oscillatory motions in which the internal energy of the oscillatory motion remains a constant. The second type of oscillatory motions is the damped oscillatory motions. In the case of damped oscillatory motions, the internal energy of the oscillatory motion decreases over time. The third type is the forced oscillatory motions. In forced oscillatory motions, a force is applied on the pendulum in a periodic variation to the pendulum.