U4-WAVES: Mechanical Waves and Propagation

Comprehensive vocabulary flashcards covering wave properties, types of mechanical waves, wave anatomy, units of measurement, and propagation methods based on the lecture notes.

Wave

A vibration that transfers NRG from one place to another.

Mechanical waves

Waves that transfer NRG but do not transfer matter.

Longitudinal wave

A type of wave where particles move back and forth in the same direction as the wave; it can travel through solid, liquid, and gas, but not through a vacuum.

Compression

A part of a longitudinal wave where particles are close together, resulting in high density and pressure.

Rarefaction

A part of a longitudinal wave where particles are spread apart, resulting in low density and pressure.

Transverse wave

A wave where the particles move up and down while the wave itself moves forward.

Crest

The highest point of a transverse wave.

Trough

The lowest point of a transverse wave.

Medium

The material (solid, liquid, or gas) through which a mechanical wave travels.

Wavelength ($\lambda$)

The length required to complete one wave cycle, such as the distance from crest to crest.

Amplitude ($A$)

The distance from the equilibrium (middle) to the crest or trough, where greater $A$ indicates more NRG; units are in meters ($m$).

Node

A point where the wave has minimal amplitude ($A$), which is important for standing waves.

Frequency ($f$)

The number of complete wavelengths that pass by a particular spot in a specific amount of time (usually one second), calculated as $f = \frac{\text{cycles}}{\text{time}}$.

Hertz ($Hz$)

The unit of frequency, where $1\,Hz = 1/s$.

Period ($T$)

The time for one wavelength to pass by a specific point, measured in seconds ($s$) and calculated as $T = \frac{\text{time}}{\text{cycles}}$.

Frequency and Period Relationship

The mathematical relationship where $f = \frac{1}{T}$ and $T = \frac{1}{f}$.

Wave propagation

The travel of a wave through a material or medium.

Circular waves

Waves created by a single disturbance at one point where NRG travels outward in all directions evenly, like a water droplet hitting a pond.

Wavefront

A line or circle where all points on the wave are the same distance from the source and in the same phase (vibrating in the same way at the same time).

Plane waves

Waves created by many disturbances over a large area that form long, straight wavefronts traveling in the same direction and speed.

Pulse

A single disturbance that moves from point to point.

Periodic wave

A series of evenly timed disturbances in a medium with evenly spaced waves of equal amplitude and constant frequency.