Different Types of Motions in Physics

In this article, we will have a look at the various kinds of Motions that we are probably going to encounter in Physics.

Table of Contents

• On the basis of the Shape of the Path
• On the basis of their Repetition
• Periodic Motion and Oscillatory Motion

Motions can be characterized in various ways.

On the basis of the Shape of the Path

Rectilinear Motion

When an object moves in a straight line, i.e. direction component of its velocity remains constant, then that object is supposed to move in a Rectilinear Motion.

Projectile Motion

When an object moves under the influence of another force, such that this external force is not in the direction of motion of the object or opposite to it, then the object starts moving in a parabolical or circular motion.

For example, when a person throws a ball to another person, it takes a parabolical path.

Can you identify Rectilinear and Projectile Motion in the following figure?

On the basis of their Repetition

Repetitive Motion

Some motions are repetitive, i.e. they repeat again and again. The time-period after which they repeat may remain the same or vary.

For example, uniform circular motion, orbits of planets around a star, motion of a pendulum, vibration of a string, etc.

Non- Repetitive Motion

On the other hand, some motions are non-repetitive. They happen once, and then they stop.

For example, a sliding bock of wood stops after sometime due to friction. It starts moving when force is applied to it, and stops due to friction. It happens one time; it does not repeat.

Periodic Motion and Oscillatory Motion

Both Periodic and Oscillatory Motions are repetitive in nature. But they differ in a very fundamental way.

Periodic Motion

When the time-period of repetition is constant, we call it a periodic motion. The same motion is repeated in the same amount of time, again and again.

It’s like watching a replay. Everything happens the same way as it happened in the previous cycle. For example, uniform circular motion, orbits of planets around a star, etc.

Oscillatory Motion

Here an object moves repeatedly in a to and fro motion about a fixed mean position. For example, a swinging pendulum, a vibrating string, etc.

Swinging Pendulum:

Vibrating String:

Oscillation versus Vibration

Oscillations and Vibrations are technically the same thing.

However, when an object moves to and fro slowly, we generally call it a vibration. For example, a swinging pendulum.

But when this to and fro motion is very rapid, we often call it vibration. For example, when strings of a guitar vibrate.

So, technically Oscillations and Vibrations are the same. But when frequency is small, we prefer to call this kind of motion Oscillation. And when frequency is large, we prefer to call this kind of motion Vibration.