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Doc Al
#2
Aug31-08, 07:06 AM
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You need to understand how to read the displacement graph. If there were no sound wave, there would be undisturbed particles at every point x. The displacement at coordinate x tells you the displacement of the particles whose undisturbed position is at x. Thus if the displacement is a maximum at point x, it means that the particles that usually reside at point x have been displaced to the right (positive direction); If the displacement is a minimum, it means they've been displaced to the left. Thus the position where the pressure is maximum would be between a maximum and minimum of displacement. Make sense?