Standing Waves

As two waves moving in opposite directions interference the standing wave is formed. For example interference of wave with its reflection

• Does not propagate but remains stationary i.e. no net propagation of energy
• The amplitude is a superposition of its componenets
• Node: no motion. Antinode: maximum motion

Longitudal standing waves are present in flute, pipe, clarinet etc.. in which the air column in the tube resonates at some characteristic frequencies (harmonics) of the external sound. The longest possible wavelength is called first harmonic (fundamental)