Wave and Wave Motion Vocabulary

Vocabulary flashcards covering key definitions, mathematical relationships, wave properties, and historical figures from the lecture notes on Wave and Wave Motion.

Mechanical wave

A type of wave that requires a physical substance (solid, liquid, or gas) to travel through and cannot travel through a vacuum.

Medium

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

Electromagnetic wave

A wave that does not require a medium and can travel through a vacuum at a speed of $3 \times 10^8$\,$\text{m\,s}^{-1}$.

Travelling wave

A disturbance that travels outward from the source producing it, transferring energy from one place to another without transferring matter.

Periodic travelling wave

A wave formed by a continuous series of identical wave pulses moving regularly outward from a vibrating source.

Transverse wave

A wave in which the direction of particle vibration is perpendicular to the direction in which the wave travels.

Longitudinal wave

A wave in which the direction of particle vibration is parallel to the direction in which the wave travels.

Rest position

The equilibrium position of the medium's particles when no wave disturbance is passing through.

Amplitude

The maximum displacement of any particle in a wave from its rest position.

Oscillation (or cycle)

The disturbance produced by one complete vibration of the wave source, consisting of one crest and one trough in a transverse wave or one compression and one rarefaction in a longitudinal wave.

Wavelength

The distance from any point on one wave cycle to the corresponding point on the next cycle, represented by the symbol $\lambda$ and measured in metres.

Frequency

The number of wave cycles passing any given point per second, denoted by $f$ and measured in hertz.

Hertz

The SI unit of frequency, abbreviated as $\text{Hz}$, where $1\,\text{Hz} = 1\,\text{cycle per second} = 1\,\text{s}^{-1}$.

Time period

The time taken for one complete wave cycle or oscillation to pass a given point, denoted by $T$ and related to frequency by $T = \frac{1}{f}$.

Velocity of a wave

The distance travelled by one wave cycle in one second, calculated using the equation $v = f\lambda$.

Compression

A region in a longitudinal wave where the particles or coils of the medium are pressed close together.

Rarefaction

A region in a longitudinal wave where the particles or coils of the medium are spread far apart.

Crest

The point of maximum upward displacement in a transverse wave above the rest position.

Trough

The point of maximum downward displacement in a transverse wave below the rest position.

Wave energy relationship

The principle stating that the energy carried by a wave is directly proportional to the square of its amplitude ($\text{Energy} \propto (\text{amplitude})^2$).

Heinrich Rudolf Hertz

A German physicist (1857–1894) who discovered radio waves, demonstrated the existence of electromagnetic waves, and discovered the photoelectric effect in 1887.

James Clerk Maxwell

The physicist who proposed the mathematical theory of electricity and magnetism that predicted electromagnetic waves.