1-) Column AB consist of a W250 x 58 rolled steel shape made of a grade of steel for which oy= 250 MPa and E = 200 GPa. Determine the allowable centric load P. a) if the effective length of the column is 7.2m in all directions b) if bracing is provided to prevent the movement of the midpoint C in the xz plane. (Assume that the movement of point C in the yz plane is not affected by bracing.) 3.6 m 7.2 m 3.6 m (a) (b)