Standing waves in a phone pole [closed]

Consider a telephone pole having standing waves generated in its length by prevailing winds. If the length of the pole above the ground is 25m and the speed of sound through the pole is 75m/s what is the fundamental frequency? What is the third harmonic frequency? Why is an oscillating phone pole similar to an oscillating tuning fork?

Can we assume that the pole behaves like a pipe open on the top and closed at the bottom? In that case the fundamental wavelength is $\lambda=4\times 25=100m$ and the frequency is $f=75/100=0.75 Hz$?

What is the third harmonic frequency? That would be $f=75/20=15/4 Hz$?

Why is an oscillating phone pole similar to an oscillating tuning fork?