A string stretched between two supports sets up standing waves with two nodes between the ends when driven at a frequency of 230 Hz. At what frequency will it have three nodes? What order harmonic is such a wave? What is the fundamental frequency? For the first question, I don't have anything to start with. The problem doesn't give the distance between the supports, the amplitude or anything. For the second question, what is the definition of 'order harmonic?' The last question I think I can figure out if I solve the first one.