When one or more waves reach the same point at the same time, their displacements (whether they are positive or negative) simply add to determine the net displacement.
Work Step by Step
This is discussed on page 363.
You can help us out by revising, improving and updating this answer.Update this answer
After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.