If a traveling wave has amplitude of d, it feels certain amount of force at that moment in time when it is displaced for equilibrium. Thus there is also strain on the string corresponding to that amount.
However, I'm curious of what happens to the strain on the string at the moment when two waves destructively interfere to create the same wave of same amplitude of d. Would it be the same as the previous case? Or would it be larger because it is the outcome of two waves pulling towards different direction?
So in essence, I want to know if concept of superposition is a priori to related phenomena or if it is a simple description to the outcome of related phenomena.