# A fourth harmonic standing wave is set up in a 3 m long guitar string. If the frequency of the wave is 191 Hz, what is its velocity?

If the length of the guitar is $l$,then for $4$ th harmonic $\lambda = \frac{2 l}{4} = \frac{l}{2} = \frac{3}{2} = 1.5 m$
Now,using $v = \nu \lambda$
Given, $\nu = 191 H z$
So,v=191×1.5=286.5 ms^-1