1. The problem statement, all variables and given/known data Apply the principle of superposition to draw the resultant shape when each of the sets of pulses shown interferes. (Draw the diagrams so that the horizontal midpoints of the pulses coincide.) 2. Relevant equations Please check this website: http://myclass.peelschools.org/sec/11/22607/Lessons/Unit 4 Sound/Review Chapter 6.pdf and look at #20, page 2. I have to do every diagram but I want to learn and so letter a. 3. The attempt at a solution Do I draw amplitude arrows going down.. eek, I'm so confused, please help!