Science
Sound.
Definition
Sound is a mechanical wave that travels through matter (solids, liquids, and gases) as vibrations of particles. It cannot travel through a vacuum because it requires a medium. Sound waves are longitudinal, meaning particles vibrate parallel to the direction of wave travel.
Examples
Real-world.
- 1 A guitar string vibrating and pushing air molecules to create sound
- 2 Thunder heard after lightning because sound travels slower than light
- 3 Sonar using sound waves underwater to map the ocean floor
Key Fact
Speed of sound in air ≈ 343 m/s at 20°C; faster in solids and liquids