GenSci 0.5 Lights and Sounds

Wave

A disturbance that carries energy from one place to another without transferring matter.

Wavelength (λ)

The distance between successive crests or troughs.

Frequency (f)

How many crests or troughs pass a specific point during a unit of time.

Amplitude (A)

The height of a wave.

Wave Speed (v)

Can be expressed as the wavelength multiplied by the frequency (v=λf).

Transverse Wave

"Vibrations of particles are perpendicular to the direction of travel (Ex: Light, water waves, rope waves)."

Longitudinal Wave

"Vibrations of particles are parallel to the direction of travel; requires a medium (Ex: Sound, P-waves)."

Light

A transverse wave that is part of the electromagnetic spectrum; does not need a medium to propagate.

Light Wave Speed

Travels very fast at a constant speed (3×108 m/s in vacuum).

Light Wavelength

Corresponds to the colors of light (red has a longer λ than blue).

Light Frequency

Corresponds to the energy of light (red has a lower f than blue).

Light Amplitude

Relates to brightness (greater Amplitude = brighter light).

Light Intensity

The amount of light per area (higher intensity = brighter light).

Reflection (Light/Sound)

The light/sound wave bouncing off a surface.

Absorption (Light/Sound)

Energy taken in by a medium (light) or converted when striking a medium (sound).

Refraction (Light/Sound)

The light/sound wave bending when passing into a new medium.

Transmission (Light/Sound)

The light/sound wave passing through a medium.

Diffraction (Light/Sound)

The light/sound wave bending around an obstacle or through a small opening.

Scattering (Light)

Random redirection of light.

Diffusion (Sound)

Random scattering of sound.

Interference (Light/Sound)

Light/sound waves combining.

Sound

"A longitudinal, mechanical wave that needs a medium to propagate and is produced by vibrating objects."

Sound Wave Speed

"Faster in solids; slower in gases."

Sound Wavelength

Corresponds to pitch (longer λ = lower pitch).

Sound Frequency

Corresponds to pitch (higher f = higher pitch).

Sound Amplitude

Corresponds to loudness (greater A = louder sound).

Sound Intensity

The amount of sound per area (higher intensity = shouting).

Quality (Timbre)

The uniqueness of a sound.

Infrasonic

Sound waves that have frequencies below 20 Hz.

Human Hearing

The range of human hearing is approximately 20 Hz to 20 kHz.

Ultrasonic

Sound waves that have frequencies above 20 kHz.