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Q4(a) A steel column that is fixed at the base and free at the top is constructed of a wide-flange section (See Figure Q4). The column height is L = 3 m. The yield stress is oy = 250 MPa and the modulus of elasticity is E = 200 GPa for the steel column. (a) Due to the design need, the compressive force P acting at the top of the column has an eccentricity e = 60 mm. Determine what is the maximum allowable load Pallow? (12 marks) (b) If the compressive force P is applied without any eccentricity, determine the maximum allowable concentric load. Comment on the effect of eccentricity based on the comparison of two load capacities. (5 marks) Hint: The secant formula for a column subjected to an eccentric compressive load is L max = L = KL A 2r VEA ec 1+ sec 1 205mm DI 9.4mm H A A 310mm L 16.3mm Section A-A Figure Q4 Q4(b) Explain the meaning of "slenderness ratio" of a column. Use formulas or figures in your explanation if necessary. (3 marks)