Glossary
Amplitude (A)
The maximum displacement or distance moved by a point on a vibrating body or wave measured from its equilibrium position.
Example:
The louder a sound, the greater the amplitude of its sound waves, meaning the air molecules are displaced more from their resting positions.
Angular Frequency (ω)
A measure of the rate of rotation or oscillation, expressed in radians per second, and related to frequency by ω = 2πf.
Example:
In the equation for a simple harmonic oscillator, the angular frequency determines how quickly the oscillation completes a cycle.
Frequency (f)
The number of complete wave cycles that occur in one second, measured in Hertz (Hz).
Example:
A radio station broadcasting at 98.7 MHz means its radio waves have a frequency of 98.7 million cycles per second.
General Wave Equation
A partial differential equation that describes the relationship between the displacement of a wave and its time and space variables.
Example:
Physicists use the general wave equation to model various phenomena, from vibrating strings to electromagnetic radiation.
Longitudinal Wave
A type of wave where the oscillations of the medium are parallel to the direction of wave propagation.
Example:
Sound waves are longitudinal waves because the air molecules vibrate back and forth in the same direction that the sound travels.
Period (T)
The time it takes for one complete wave cycle to pass a given point.
Example:
If a buoy bobs up and down every 2 seconds as waves pass, the period of those waves is 2 seconds.
Periodic Wave
A wave that repeats its pattern over and over again, characterized by consistent wavelength, period, frequency, and amplitude.
Example:
The consistent ripples created when a steady drip of water hits a pond's surface form a periodic wave.
Speed (v)
How fast a wave is traveling through a medium, calculated as the product of its frequency and wavelength (v = fλ).
Example:
Light travels at an incredibly high speed in a vacuum, approximately 3 x 10^8 meters per second.
Transverse Wave
A type of wave where the oscillations of the medium are perpendicular to the direction of wave propagation.
Example:
When you pluck a guitar string, the string vibrates up and down, but the wave travels along the string, making it a transverse wave.
Waveform
The shape or graphical representation of a wave, illustrating its displacement over time or position.
Example:
A pure musical note often has a smooth, sinusoidal waveform, while a complex sound might have a jagged, irregular one.
Wavelength (λ)
The distance between two identical consecutive points on a wave, such as from crest to crest or trough to trough.
Example:
If you measure the distance between two consecutive peaks of an ocean swell, you're finding its wavelength.