7. True stress-strain curve of an annealed copper is represented in the following image. Calculate the constants of power law equation that represents such stress-strain behavior. 800 700 600 500 400 300 200 100 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 True strain True stress (MPa) 8. For the material of problem 7, calculate Forging Force in upsetting. To what thickness can a solid cylinder of such material that is 60 mm in diameter and 70 mm high be forged in a press that can generate 480 kN?