Physics / Superposition
When waves reinforce
and cancel
Two waves. One string. Add their displacements at every point to see what the string actually does.
x = 0 → 8 length unitsVertical: displacement units
Wave 1 · +xWave 2 · −xActual sumStanding node
At the marked point · x = 1
Wave geometry
Marked material pointUp and down onlyIts x coordinate never changes.
0° · aligned180° · opposed360°