Standing waves

Science

Definition

Standing waves form when two waves of the same frequency and amplitude travel in opposite directions and interfere, creating a pattern of nodes (points of no displacement) and antinodes (points of maximum displacement). They appear to vibrate in place rather than travel.

Examples

  • A guitar string vibrating at its fundamental frequency and harmonics
  • Organ pipes producing sound through standing air column vibrations
  • Microwaves creating hot and cold spots in a microwave oven
Key Fact

For a string fixed at both ends: λₙ = 2L/n, where n = harmonic number

Related Terms

Wave properties Sound waves Interference Resonance

Study This Concept

Practice standing waves with free review games in these units:

AP Physics 1 Unit 7: Waves and Sound