A rectangular cross-section column has dimensions of cross section b = 50 mm and h = 120 mm. The column is pin supported at ends A and B, with end B free to move in the vertical direction as shown in Figure Q4. At the middle the column is restrained in the plane of the figure but free to deflect in the plane perpendicular to the plane of figure. a) Determine through calculations whether the column buckles in the elastic or plastic regime. [10 marks] b) If the elastic modulus of the material of the column is 200 GPa and force P is equal to 200 N find the critical stress in the column assuming elastic behaviour. [4 marks] c) Calculate the ratio b/h for which the critical load is the same for buckling in the two planes of the column (i.e. in the plane of drawing and perpendicular to the plane of the drawing). [6 marks] P B wwwwwww A ALUVIAL 1.5 m 1.5 m Figure Q4 Section A-A (not at scale) b