2. Determine the total deformation of the steel rod (AD) under the given loads (assuming Young's modulus of both parts E = 200 GPa. The cross-sectional area and the original length of each part is labeled). A = 0.9 cm² A A = 0.3 cm² B C D 6 kN 13.5 kN 1.5 kN -16 cm- 12 cm 12 cm