A steel bar has a rectangular cross section as shown. It is fixed to the wall at point A, and when the bar is not loaded, there is a 0.05 mm gap between the bar and wall at point C. A 20 kN and a 10 kN forces are applied at points B and C, as shown. If the modulus of elasticity of the bar is 200 GPa, determine the normal stress in this element. [25] 20 kN 10 kN A Ko.4m 0.6 m * 20 mm 0.05 mm Cross Section mm