Superposition of Waves
When two (or more) waves of the same nature each produce a wave in a medium, the waves interfere with each other. The amplitude of the combined wave is equal to the sum of the amplitudes of the component waves. This process is called superposition and the combination wave is the resultant wave. Even though waves will interfere with each other when they occupy the same positions in a medium, they will continue their initial propagation unaltered.
Constructive interference: The two waves travelling in opposite directions add together.
Destructive interference: The two waves add and effectively cancel each other.
Use the simulation below to explore the interference of wave pulses. Experiment with waves of various width and various heights, including negative height pulses interfering with positive height pulses.