Wave Motion - Mission WM6 Detailed Help

The diagram below shows two pulses - a square pulse and a triangle pulse - approaching each other along the same medium. Which diagram shows the shape of the medium when they are completely interfering?

Principle of Superposition:
When two waves traveling along the same medium interfere with each other, the medium takes on a new size and shape which is the result of the combination of the size and shape of the two interfering waves. The resulting displacement of the medium at any given location can be determined by adding the vector displacements caused by each individual wave at that location. When adding the displacements of the individual waves, their direction of displacement must be considered in addition to the amount of displacement.

When the square crest meets the triangle crest (or sine crest), the resulting shape of the medium would be the result of adding the two pulses. One way to determine the answer is to visually overlap the two pulses. Then select about three locations along the medium and apply the principle of superposition.