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Wave Interference - help8

When two or more waves meet up while traveling through the same medium, they undergo interference. The amount that the medium is displaced from its usual resting position is dependent upon the contribution of each individual wave that is interfering.

There are two similar versions of this question. Here is one of the versions:

Version 1:

Wave 1 (in Red) and Wave 2 (in Blue) are moving through the same medium and undergoing interference. The displacement of the medium at each location will depend upon the individual displacements of the two waves at that location. For the three labeled locations, determine the nearest estimate of the resulting displacement of the medium. (Each small square is 0.10 m along its edges.)

At location A, the resulting displacement is _______ m.
At location B, the resulting displacement is _______ m.
At location C, the resulting displacement is _______ m.

When two waves travel along the same medium, each wave exerts its own individual effect upon the medium. That is to say that each waves either pulls upward ("positive" direction) or pulls downward ("negative" direction) upon the medium by a given amount. But the medium can have only one response. It can't show both waves; it must show the combined effect of both waves. And this combined effect is easily determined by simply adding the two individual effects. This is known as the Principle of Superposition.

To determine the effect at each location, simply add the displacement of both waves at that location. That is, measure (or count) upward (or downward) to the red wave to determine the displacement of the medium that would result from the red wave acting alone. Repeat this measurement (or count) for the blue wave. Add the two numbers together and the result is the combined displacement at that location for the two waves acting together. Note that one or both of the numbers that you are adding together could be negative (for downward).

Try this link to The Physics Classroom Tutorial for more help with understanding wave interference:

Interference of Waves