1. The problem statement, all variables and given/known data A 7 metre long string is stretched between 2 walls so that its ends are fixed. It is made to vibrate and it is found that the displacement, y is given by: y = 0.023sin(xpi)cos(0.714 pi t) where x and y are in metres and t is in milliseconds. a) to which harmonic, N, does the vibrtion correspond? b) What is the frequency of the sound emitted by the string? c) What is the speed of waves in the string? 2. Relevant equations y(N) = 2y sin((Npix)/L)cos((vNtpi)/L) 3. The attempt at a solution To get part a, can u use the formula and see that L must equal N in order to get the equation in the question, or no? I'm lost.