Introduction to Waves and Sound

This set of 19 flashcards defines fundamental wave properties, types of waves, and specific characteristics of sound waves and human hearing based on the lecture notes.

Wave

Transfers energy from one place to another through vibrations.

Transverse wave

A wave where the particles vibrate at $90^\circ$ to the direction of the wave.

Transverse wave examples

Water waves, waves on strings and ropes, and electromagnetic waves.

Longitudinal wave

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

Longitudinal wave example

Sounds waves.

Examples of waves

Radio, Micro, Infrared, Visible light, UV, X-Ray, Gamma, Sound, Water, and Ultrasound.

Amplitude

The furthest distance of the wave from its rest position, which is measure in metres ($m$).

Frequency

The number of complete waves that pass a point in one second, which is measure in Hertz ($Hz$).

Wavelength

The distance between one point on a wave and the same point on the next wave, measured in metres ($m$).

Crest and trough

A crest is the top of a wave, and a trough is the bottom of a wave.

Compressions and rarefactions

Compressions are where particles bunch together; rarefactions are where particles are far apart.

Sound wave production

Produced by vibrations.

Sound wave transmission

Travels through materials such as air, glass, and water; sound cannot travel in a vacuum as there are no particles to carry the vibrations.

Sound travel materials

Sound travels fastest in solids, then liquids, and then gases.

Loudness

A sound becomes louder as the amplitude of the wave increases.

Pitch

A sound becomes higher pitched as the frequency of the wave increases.

Hearing range

For most people, the frequency range of hearing is between $20\,Hz$ and $20,000\,Hz$.

Hearing and aging

The phenomenon where a person’s upper frequency limit decreases as they get older.

Echoes

Reflections of waves.