Question

two wave pulses move toward each other along a rope. which diagram shows the resulting wave when they cross at point x?

Explanation:

Step1: Principle of superposition

When two wave pulses move toward each other, at the point of overlap (point X), the displacements of the waves add up. If we consider the amplitudes of the two wave pulses, when they cross, the positive displacements from each wave combine.

Step2: Analyzing the wave shapes

The first wave has an upward - going triangular - like shape on the left, and the second wave has an upward - going triangular - like shape on the right. When they meet at point X, the superposition of these two pulses (assuming they have the same amplitude and wavelength in the overlapping region) results in a region where the displacement is the sum of the individual displacements. This sum gives a flat - topped (in the overlapping region) wave, which is represented by the third diagram.

Answer:

Third option (the one with a flat - topped rectangular - like shape)