1. The problem statement, all variables and given/known data A series of pulses, each with an amplitude of .150 m are sent down a string that is attached to a post at one end. The pulses are reflected back and travel back along the string with no loss of amplitude. What is the net displacement of an element at a point on the string where the 2 pulses cross a. if the string is rigidly attached, b. if the end at which reflection occurs is free to slide up and down. 2. Relevant equations I know that in a rigidly fixed string, reflection inverts the waves, and if the string is free to move up and down, the reflected pulse is not inverted. 3. The attempt at a solution I am thinking that in a rigid system, the net displacement where the two pulses cross would be zero, because that point would be a node. If the system is free to move, then I think that the net displacement at the point where the waves meet would be plus or minus A. Is my brain working right?