Wave Properties, Doppler Effect, and Propagation Speeds

Vocabulary flashcards covering core wave concepts, Doppler effect, propagation speeds in various mediums, electromagnetic wave properties, and wave measurement definitions.

Doppler Effect

A phenomenon where relative motion between a source and observer alters frequency and wavelength only, leaving wave speed, brightness, and amplitude unchanged.

Blueshift

The effect observed when a light source moves toward an observer, resulting in an increased frequency and a decreased wavelength.

Redshift

The effect observed when a light source moves away from an observer, resulting in a decreased frequency and an increased wavelength.

Wave Propagation

The process by which waves transport energy and information across distances while medium particles merely vibrate in place.

Speed of Sound in a Vacuum

$0\,\text{m/s}$; sound cannot travel in a vacuum because it strictly requires a physical medium.

Speed of Sound in Air (Gas)

Approximately $\sim 340\,\text{m/s}$, which is relatively slow compared to its speed in liquid or solid mediums.

Speed of Sound in Water (Liquid)

Approximately $1500\,\text{m/s}$, which is faster than in air but slower than in dense solids.

Speed of Sound in Glass (Solid)

The fastest medium speed for sound waves, adhering to the rule that sound propagates fastest in dense solids.

Speed of Light in a Vacuum

The maximum speed of electromagnetic waves, equal to $3 \times 10^8\,\text{m/s}$.

Core Speed Rule for Sound Waves

Sound requires a medium to propagate and travels fastest in dense solids.

Core Speed Rule for Light Waves (EM)

Light does not need a medium to propagate and travels fastest in a vacuum.

Universal EM Speed

The rule that all electromagnetic waves, including radio waves, visible light, and X-rays, travel at the exact same speed ($c$) in space.

Radio Waves vs. Visible Red Light

Radio waves have lower frequency, longer wavelengths, and lower energy compared to visible red light.

Wave Amplitude

The wave measurement that determines brightness in light waves and volume or loudness in sound waves.

Wave Frequency

The wave measurement that determines color in light waves and pitch in sound waves.

Wavelength ($\lambda$)

The distance required for one complete wave cycle, measured crest-to-crest, trough-to-trough, or across one full S-shape.

Destructive Interference

An interaction occurring when a wave crest aligns with a trough, temporarily canceling out wave amplitude.

Constructive Interference

An interaction occurring when two wave crests or two troughs align, temporarily reinforcing and increasing wave amplitude.

Wave Medium Speed Summary Table

A visual guide contrasting sound and light wave speeds across a vacuum, air, water, and glass.