A one degree-of-freedom model of a 9-m steel flagpole (p = 7400 kg/m³, E = 200 × 10° N/m², G = 80 × 10° N/m²) is that of a beam fixed at one end and free at one end. The flagpole has an inner diameter of 4 cm and an outer diameter of 5 cm. (a) Approximate the natural frequency of transverse vibration. (b) Approximate the natural frequency of torsional vibration.