Wave Keywords and Definitions

Vocabulary terms covering basic wave physics, properties of sound, and properties of light based on the lecture transcript.

Wave

A disturbance that transfers energy from one place to another without transferring matter.

Medium

The substance or material that a wave travels through.

Mechanical Wave

A wave that requires a medium to travel through.

Electromagnetic Wave

A wave that does not require a medium; it can travel through a vacuum.

Transverse Wave

A wave where particles vibrate perpendicular to the direction of energy transfer.

Longitudinal Wave

A wave where particles vibrate parallel to the direction of energy transfer.

Crest

The highest point (peak) of a transverse wave.

Trough

The lowest point (valley) of a transverse wave.

Amplitude

The distance from the equilibrium to the crest or trough.

Wavelength

The distance between two consecutive identical points on a wave (e.g., crest to crest).

Frequency

The number of complete waves passing a point in one second, measured in Hertz ($Hz$).

Period

The time taken for one complete wave to pass a point.

Speed

How fast the wave travels ($\text{Speed} = \text{Frequency} \times \text{Wavelength}$).

Sound

A mechanical, longitudinal wave produced by vibrations.

Pitch

How high or low a sound is, determined by frequency.

Loudness / Volume

How strong or quiet a sound is, determined by amplitude, measured in decibels ($dB$).

Echo

A reflected sound wave.

Ultrasound

Sound waves with a frequency higher than human hearing ($>20,000\text{ Hz}$).

Infrasonic

Sound waves with a frequency lower than human hearing ($<20\text{ Hz}$).

Vacuum

A space completely empty of matter; sound cannot travel through it.

Light

An electromagnetic, transverse wave that travels at $300,000\text{ km/s}$ in a vacuum.

Ray

A straight line that represents the path of light energy.

Reflection

The bouncing of light off a surface.

Refraction

The bending of light as it changes speed when passing from one medium to another.