A cantilevered steel pipe tower, 80 m tall is being considered for a new wind turbine. The weight of the turbine is 3,400 kN. The tower under consideration will have a constant outer diameter of 4 m and a wall thickness of 6 cm. The turbine is to have three blades. The nominal rotor speed is 12 rpm. Would the tower be considered stiff, soft or soft-soft? Suppose that a tapered tower is being considered instead. How would the natural frequency be analyzed? Assume that the weight density of steel is 76.8 kN/m3 and its elasticity is 2.07 x 1011 Pa.