Question 6 (10 points): The three-bar truss ABC shown in the figure has a span L = 3 m and is constructed of steel pipes having cross-sectional area A = 3,900 mm and modulus of elasticity E = 200 GPa. A load P = (650,000 + UV) Newton acts horizontally to the right at joint C, where UV are last two digits of your student number. Note that point A is fixed, and point B is immovable in vertical direction but movable in horizontal direction. Find: (a) the axial forces in the bars, based on the force equilibrium of points C and B, (b) the strain energy of the truss (i.e., the total strain energy of bars AC, BC and AB), (c) the horizontal displacement of point C, based on the Work-energy principle. Hint: 1. The lengths of AC and BC are: LAC = LBC = L sin 45 = 2,121 mm Force Length 2. For an axial member, the strain energy is 2 EA 45 45% B L