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?
y(N) = 2y sin((Npix)/L)cos((vNtpi)/L)
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.