The formation of a standing wave requires ?

the traveling of a wave for a long distance.

constructive interference between two waves of
slightly different frequencies.

that refraction and diffraction occur at the same time in a wave.

interference between incoming and reflected waves.

Question

The formation of a standing wave requires ?
 
the traveling of a wave for a long distance.

constructive interference between two waves of 
slightly different frequencies.

that refraction and diffraction occur at the same time in a wave.

interference between incoming and reflected waves.

turingtest · Answer

This question would probably do better in the physics section, so I would suggest posting there