The discussion clarifies the relationship between longitudinal waves and their graphical representations, specifically focusing on pressure/position and displacement/position graphs. At displacement zero, a longitudinal wave can represent either a compression or rarefaction, depending on the molecular movement. Compression peaks occur when molecules are densely packed, resulting in displacements directed towards the compression point, averaging to zero. Conversely, rarefaction peaks occur when molecules are spread apart, with displacements directed away from the rarefaction point, also averaging to zero.
PREREQUISITESStudents of physics, educators teaching wave mechanics, and professionals in acoustics or related fields will benefit from this discussion.
turin said:You can think of it as the average of what the molecules are doing there. The compression peaks occur where the molecules are coming together, so the displacements of the molecules are all directed towards that point and they average out to zero. Similarly for rarefaction, except that they are direcected away from that point.