Sound

Definition

Sound is a form of energy that propagates through a medium as a mechanical wave, typically in the form of longitudinal waves. It is produced by vibrating objects and is perceived by our ears.

5 Must Know Facts For Your Next Test

1. Sound travels faster in solids than in liquids and gases due to closer particle spacing.
2. The speed of sound in air at room temperature (20°C) is approximately 343 meters per second.
3. The frequency range of human hearing is roughly 20 Hz to 20,000 Hz.
4. Sound intensity decreases with distance according to the inverse square law.
5. The Doppler effect describes the change in frequency or wavelength of sound from a moving source relative to an observer.

Review Questions

• What factors affect the speed of sound in different media?
• How does the Doppler effect explain changes in pitch for a moving sound source?
• What is the typical range of frequencies that humans can hear?

Related terms

Frequency:

The number of oscillations or cycles per unit time, measured in Hertz (Hz).

Wavelength:

The distance between successive crests or troughs in a wave, typically measured in meters.

Amplitude:

The maximum displacement from the equilibrium position in a wave, related to its loudness.