Module 5 – Mechanical Waves and Sound: Key Vocabulary

Vocabulary flashcards covering the essential terms and definitions from Module 5: Mechanical Waves and Sound.

Wave

A disturbance that travels through a medium or space, transporting energy without necessarily transporting matter.

Medium

A substance (solid, liquid, or gas) that allows a wave to propagate by transmitting its energy.

Mechanical Wave

A wave that requires a medium to travel; can be transverse or longitudinal (e.g., sound, water, seismic waves).

Electromagnetic Wave

A transverse wave that can travel through a vacuum without a medium (e.g., light, microwaves, X-rays).

Transverse Wave

A wave in which particle oscillations are perpendicular to the direction of wave propagation; features crests and troughs.

Longitudinal Wave

A wave in which particle displacements are parallel to the direction of propagation; features compressions and rarefactions.

Crest

The highest point of a transverse wave.

Trough

The lowest point of a transverse wave.

Compression

The high-pressure region of a longitudinal wave where particles are crowded together.

Rarefaction

The low-pressure region of a longitudinal wave where particles are spread apart.

Amplitude

The maximum displacement of a particle from its rest position; proportional to the energy carried by the wave.

Wavelength (λ)

The distance between successive identical points on a wave (e.g., crest to crest or compression to compression).

Frequency (f)

The number of complete wave cycles passing a point per unit time; measured in hertz (Hz).

Period (T)

The time it takes for one complete wave cycle to pass a point; T = 1⁄f.

Wave Speed (v)

The rate at which a wave travels through a medium; given by v = fλ.

Surface (Circular) Wave

A wave in which particles move both parallel and perpendicular to the direction of energy transfer, as in ocean waves.

Superposition Principle

When two or more waves overlap, the resultant displacement equals the algebraic sum of individual displacements.

Constructive Interference

Interference that occurs when overlapping waves have displacements in the same direction, producing increased amplitude.

Destructive Interference

Interference that occurs when overlapping waves have displacements in opposite directions, producing reduced amplitude.

Doppler Effect

The observed change in frequency (pitch) of a wave due to relative motion between the source and the observer.

Standing Wave

A stationary wave pattern formed by the interference of two identical waves traveling in opposite directions.

Node

A point on a standing wave that remains at zero displacement.

Antinode

A point on a standing wave that experiences maximum displacement.

Harmonic

A frequency that is an integer multiple of a fundamental frequency, producing resonant standing-wave patterns.

Pitch

The auditory sensation correlated with the frequency of a sound wave; higher frequency corresponds to higher pitch.