Constructive Interference

Wave pulses traveling in opposite directions with peaks on the same side of a wave demonstrator interfere constructively.

Discussion

When two wave pulses traveling on the same side of the wave demonstrator meet and pass each other, their displacements add, as predicted by the principle of superposition. This is an example of constructive interference. By stepping carefully through this movie during the period when the two pulses are passing each other, you can show that the amplitude, or maximum displacement, of the combined wave pulse at the point of maximum overlap is equal to the sum of the amplitudes of the two single pulses.