Oscillatory Motion - Definition, Examples, Types, FAQs

Oscillatory motion is the repetitive back-and-forth movement of a body about an equilibrium position which has applications in everyday life. It is necessary for understanding concepts like sound waves, and electromagnetic oscillations. In this article, we will discuss the characteristics of oscillatory motion, examples of oscillatory motion, define oscillatory motion, types of oscillatory motion, what is periodic motion, and the difference between periodic motion and oscillatory motion.

JEE Main 2025: Physics Formula | Study Materials | High Scoring Topics | Preparation Guide

JEE Main 2025: Syllabus | Sample Papers | Mock Tests | PYQs | Study Plan 100 Days

NEET 2025: Syllabus | High Scoring Topics | PYQs

This Story also Contains

1. Define Oscillatory Motion
2. Characteristics of Oscillatory Motion
3. Examples of Oscillatory Motion
4. Types of Oscillatory Motion
5. What is Periodic Motion
6. The Difference Between Periodic Motion and Oscillatory Motion

Define Oscillatory Motion

Oscillatory motion definition: The to and fro motion of an object from its mean location. Oscillatory Motion is a motion in which an object repeatedly moves over a spot. The optimum situation can be approached in a total vacuum since there will be no air to halt the item in oscillatory motion friction.
The vibration of strings and the movement of spring are oscillatory motions in the mechanical world and are the same as mechanical vibration.

Characteristics of Oscillatory Motion

• Oscillatory motion occurs at a fixed point where the net force acting is zero. This position is called the equilibrium position.
• The fixed interval of time at which the oscillatory motion repeats itself is called the time period.
• The maximum displacement from the equilibrium position called amplitude measures the extent of oscillation.
• Frequency is the number of oscillations completed per second.

$$f=\frac{1}{T}$$

• Oscillatory systems have both kinetic energy and potential energy.

Examples of Oscillatory Motion

1. Motion of a simple pendulum
2. Vibrating strings of a guitar
3. Oscillation of a tuning fork
4. The motion of a swing
5. Spring mass system
6. Bungee jumping
7. A suspension bridge under variable load

Types of Oscillatory Motion

Based on the nature of motion, oscillatory motion can be classified into two types:

1. Linear Oscillatory Motion
2. Circular Oscillatory Motion

Linear Oscillatory Motion

The oscillatory motion occurs in a linear path ( straight line) around the equilibrium position. The displacement is measured in meters or any unit of length. The restoring force is proportional to the displacement.

$$
F=-k x
$$

Examples of linear oscillatory motion

• Spring-mass system
• Vibration on a string
• The piston in an engine
• Bungee jumping

Circular Oscillatory Motion

The oscillatory motion is in back-and-forth rotation about a fixed axis. The displacement is measured as an angle. The restoring torque is proportional to the angular displacement.

$$
\tau=-k \theta
$$

Examples of Circular Oscillatory Motion

• Swinging doors
• Rotating flywheel
• Balance wheel in clocks

Simple Harmonic Motion

Simple harmonic motion is a type of oscillatory motion in which Hooke's law is obeyed. In this motion, the restoring force is directly proportional and opposite to the displacement from the equilibrium position of the motion.

$$
F=-k x
$$

where,

• $F$ is the spring's restoring elastic force ($N$),
• $k$ is the spring constant ($\mathrm{Nm}^{-1}$),
• $x$ is the displacement from the equilibrium position ($m$)

Examples of SHM

• Vibrating strings
• LC circuit
• Torsional pendulum

The oscillatory motion's equilibrium position is the place at which oscillations occur, and the oscillating object must pass through this point during each oscillation. The oscillating object comes to a stop at this point after some time when the oscillatory motion stops due to friction in the medium in which it is oscillating.

Vibration is a term used to describe objects that oscillate. There isn't much of a distinction between these two terms. However, in general, when an object moves at high frequencies, it is said to be vibrating, and when it moves at low frequencies, it is said to be oscillating.

TO and FRO Motion

The forward and backward movement of an object around an equilibrium point is referred to as to and fro. A pendulum, for example, travels from one side to the other before returning to its original position. To and fro motion is the term for this type of movement.

What is Periodic Motion

In physics, periodic motion is defined as motion that occurs at regular intervals. A rocking rocker, a bouncing ball, a vibrating tuning fork, a swing in motion, the Earth in its orbit around the Sun, and a water wave are all examples of periodic motion. Sine curves can be used to illustrate periodic waves.

Periodic motion should not be confused with oscillatory motion. Each oscillatory motion is invariably a periodic motion, while each periodic motion does not have to be oscillatory. A periodic motion might be oscillatory or non-oscillatory. The motion of a car wheel, for example, is periodic but not oscillatory, whereas the motion of a stringed object attached to a wall is both periodic and oscillatory.

The Difference Between Periodic Motion and Oscillatory Motion

The differences between oscillatory and periodic motions are given in the table below:

Also read:

• NCERT Exemplar Solutions for All Subjects
• NCERT Notes For All Subjects
• NCERT Solutions for All Subjects