Physics Study Notes - Sound and Light

Vocabulary flashcards covering key concepts from the lecture notes on sound and light.

Origin of Sound

Vibrations of material objects.

Compression

Pulse of compressed air.

Rarefaction

Pulse of lower-pressure air.

Sound Transmission Medium

Sound cannot travel in a vacuum.

Elasticity

Ability of a material to change shape in response to an applied force and then resume its initial shape.

Loudness

A physiological sensation sensed in the brain related to sound intensity, which is subjective and varies for different people.

Forced Vibration

Occurs when a music instrument is mounted on a sounding board, making the sound louder due to the larger surface setting more air in motion.

Natural Frequency

The special set of frequencies at which an object vibrates when disturbed, depending on elasticity and shape.

Resonance

A dramatic increase in amplitude that occurs when the frequency of a forced vibration matches the object's natural frequency.

Interference

Occurs when waves overlap, resulting in either constructive (increased amplitude) or destructive (decreased amplitude) effects.

Beats

A periodic variation in the loudness of sound heard when two tones of slightly different frequency are sounded together.

Music

A pleasing succession of pitches (frequencies) usually selected from a specific sequence called a scale.

Fundamental (First Harmonic)

The wave with wavelength 2L.

Fourier analysis

The technique of taking complex wave and breaking down into a sum of simple, single frequency waves.

Photons

Massless bundles of concentrated electromagnetic energy that make up light.

Light emission

Light is energy that is emitted by accelerating electric charges in atoms.

Light-year

The distance light travels in one year.

Electromagnetic Spectrum

The entire range of electromagnetic waves, including radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma rays.

Opaque Materials

Materials that absorb light without reemission, thus allowing no light to pass through.

Ray

A thin beam of light.

Umbra

A total shadow.

Penumbra

A partial shadow.

Polarized Light

Light in which the vibrations lie along the same plane.