1. What Are Vibrations?
Vibrations are rapid back-and-forth movements of an object around a central position (rest position). These movements can be small or large, but they always repeat.
Almost every sound we hear begins with some object vibrating—like a string, a membrane, or even the air inside a tube.
2. What Are Oscillations?
Oscillations are repetitive motions that move to and fro on either side of a central point. They are usually slower and more regular compared to tiny vibrations.
In simple words, oscillation is just a repeated movement that occurs in a regular pattern.
2.1. Difference Between Vibrations and Oscillations
- Vibrations are usually fast and may have small amplitudes.
- Oscillations can be slower and have larger movements.
- Both involve movement on both sides of a rest position.
3. Rest Position
The rest position is the point where the object stays when no external force is acting on it.
During vibration or oscillation, the object moves equally on both sides of this position.
3.1. Visualising Rest Position
Think of a swing hanging still. That still point is its rest position. When you push the swing, it moves back and forth around this point.
4. Time Period and Frequency
Time Period (T): The time taken to complete one full vibration or oscillation.
Frequency (f): The number of vibrations or oscillations completed in one second.
The relationship between them is:
\( f = \dfrac{1}{T} \)
4.1. Understanding the Formula
If an object vibrates very quickly, it completes more cycles per second → high frequency.
If it vibrates slowly, the time period increases → low frequency.
5. Amplitude of Vibration
Amplitude is the maximum displacement of the vibrating object from its rest position.
Larger amplitude means stronger or louder vibrations.
5.1. Example
A guitar string plucked gently has small amplitude, while a strongly plucked string has larger amplitude.
6. Examples of Vibrations and Oscillations
- A tuning fork vibrating after being struck.
- A ruler fixed on a table edge moving up and down when released.
- A swing going back and forth in a regular motion.
- A rubber band vibrating when stretched and released.