0.6m 20N 0.6m A 1.2 m long solid bar with a square cross section of dimensions 12 mm by 12 mm is supported between two points and subjected a vertical force of 20N at its mid point, as shown in the figure. The bar is made of a copper alloy, with density p = 8930 kg m-3 and elastic modulus E = 117 GPa. What is the central deflection of the bar as a result of its loading, including its self-weight? (You should take g = 9.81 m s.) Choose the one option that is closest to the correct answer. 3.25 mm O 7.15 mm 5.25 mm 4.40 mm 10.20 mm 8.45 mm