A flagpole consists of a flexible, 3.05m tall fiberglass pole planted in concrete. The bottom end of the flagpole is fixed in position, but the top end of the flagpole is free to move. What is the lowest frequency standing wave that can be formed on the flagpole if the wave propagation speed in the fiberglass is 2730 m/s?

1 answer

well if the top is an antinode and the bottom a node, then the pole is 1/4 of a wavelength long.
So the wavelength is 4 *3.05 = 12.2 meters
the wave moves a wavelength in a period so
speed = distance / time = 2730
so
2730 = 12.2 / T = 12.2 f
f = 2730/12.2
I think about 224 Hz