Given :
A rope 6m long is fixed at one end, the other end is attached to a light string so that it is free to move.
The speed of waves on the rope is 18 m/s.
To Find :
The frequency of the second harmonic.
Solution :
We know, for second harmonic wave :
Wavelength = Length of rope
Now, we know frequency is given by :
Therefore, the frequency of the second harmonic is 3 s⁻¹.