Standing Waves (DP IB Physics: SL): Revision Note

Standing Waves

• Standing waves are produced by two waves as they travel in opposite directions

• This is usually achieved when a travelling wave superimposes its reflection

  • The superposition produces a wave pattern where the crests and troughs only move vertically

Formation of a stationary wave on a stretched spring fixed at one end

Formation of Standing Waves

• Standing waves are formed from the principle of superposition. This is when:

Two waves travelling in opposite directions along the same line with the same frequency superpose

• The principle of superposition applies to all types of waves i.e. transverse and longitudinal, progressive and stationary

• The waves must have:

  • the same wavelength

  • a similar amplitude

• As a result of superposition, a resultant wave is produced

Standing waves produced at varying frequencies

Comparing progressive and standing waves

• Standing waves (or stationary waves) store energy

• Progressive waves (or travelling waves) transfer energy

• The table below outlines the main differences between progressive and stationary waves

Table of differences between progressive and stationary waves