A radio tower is usually subjected to strong winds. The force of the wind can be modeled as a sinusoid varying force of amplitude 5 kN and frequency 0.5Hz.

Calculate the resulting maximum dynamic displacement of the tip of the tower.

For the purpose of the exercise, consider the tower as a square post having the following properties:

length 60 m and equivalent section A=0.0625m2

equivalent stiffness: I=0.007m2

density ?=7000 kg/m3

damping coefficient 0.25

Modulus of elasticity: E=210 GPa

Wind