Question

A guitar string is 6.7 m long. What is the wavelength of a third harmonic standing wave?

Answer 1

For a guitar,its length `l` corresponds to distance between to nodes i.e `lambda/2` ,where, `lambda` is the wavelength.

So,for fundamental frequency or `1` st harmonic `l=lambda/2`

or, `lambda =2l`

for, `3` rd harmonic, `lambda =(2l)/3=(2*6.7)/3=4.467m`