T 3.6 m A 4 m 20 mm 20 mm+ B A G 4P P E F 5m 5m 5m FIGURE Q8(a) 20 mm 80 mm 120 mm Column AG FIGURE Q8(b) H 120 mm, 150 mm Column FH Column AG and column FH, which has fix and pin support, respectively, are supporting a truss as shown in Figure Q8(a). Both columns are pin connected to the truss and have cross sections as shown in Figure Q8(b). (b) Determine the maximum value of P so that neither one of the columns will fail due to buckling. The modulus of elasticity, E, of both columns is 12 kN/mm. (10 marks) If P = 20 kN, determine the diameter of the truss member required so that the truss members will not fail due to buckling or yielding. The modulus of elasticity, E, and the yield stress, oy, is 200 kN/mm and 250 N/mm, respectively. Apply factor of safety of 2. (10 marks) (20 marks)