Fundamentals of Waves, Oscillation, and Sound Physics

Understanding Periodic Motion and Oscillation

Phenomena that are repeated at regular intervals of time are called periodic phenomena.

The periodic motion where a body moves from any position until it returns to that position, moving in the same direction, is called an oscillation or complete cycle.

Characteristics of Periodic Motion

Periodic motion is characterized by its period and its frequency:

• Period: The time duration required for one full cycle or oscillation of a periodic phenomenon.
• Frequency: The number of complete cycles or oscillations performed per unit time.

Oscillatory Movement Definitions

In an oscillatory movement:

• Elongation: The distance between the body's position at a particular time and the central or equilibrium position.
• Amplitude: The maximum value of elongation; the distance between the extreme position and the equilibrium position.

Wave Propagation and Characteristics

Wave movement (or wave propagation) is defined as the spread of an oscillatory movement or vibration through a medium.

A wave is a disturbance that propagates through a medium without transporting matter.

Types of Waves

Waves are classified based on the direction of particle vibration relative to propagation:

• Transverse Wave: The particles of the medium vibrate perpendicular to the direction of wave propagation.
• Longitudinal Wave: The particles of the medium vibrate in the same direction as the wave propagation.

Wave Properties

• Wavelength: The distance between two consecutive points that are in phase.
• Speed of Wave Propagation: This speed depends on the characteristics of the medium in which it propagates. The speed is constant for a given medium under specific conditions.

Some of the most important properties of waves include:

• Reflection
• Refraction
• Interference
• Absorption

The Physics of Sound

Sound is a vibration transmitted in the form of longitudinal waves. Sound does not propagate in a vacuum.

Qualities of Sound

Sound is characterized by three main qualities:

1. Intensity: The quality that allows us to distinguish sound as strong or weak.
2. Pitch (Tone): The quality that identifies sound as high (acute) or low (grave).
3. Timbre: The quality that allows us to distinguish two sounds of equal intensity and pitch.

Measuring Loudness

Loudness (Physiological Intensity) is the sensation of intensity perceived by our ears. It is measured using a sound level meter. The unit of loudness is the decibel (dB).

How We Hear Sound

The process of hearing involves several steps:

1. Sound waves penetrate the external ear canal.
2. They cause the eardrum to vibrate.
3. This vibration is transmitted to the inner ear by a chain of ossicles (little bones).
4. In the cochlea, these vibrations are converted into electrical impulses.
5. These impulses communicate with the brain via the auditory nerve, producing the sensation of sound.