Translations:One-dimensional waves/19/en

The behavior of a single pulse traveling in one direction is easily visualized. But what happens when one pulse moves from right to left at the same time that another pulse moves from left to right? As we know, the two pulses superimpose when they meet. The best way to understand this phenomenon is by means of a motion picture. Suppose two pulses start at opposite ends of the same string at the same time and head toward each other. The pulses approach each other as if each had the string to itself. As they cross each other, the two pulses additively combine to form a composite shape. But after they cross, they again assume their original shapes and travel along the string as if nothing had happened. If we perform this experiment over and over with different pulses, we always get the same result.