A carbon steel alloy (E= 30´10 6 psi) specimen is undergoing a tensile test. The initial gauge length of the specimen is 1 inch and the initial cross-sectional area is 0.25 in2 . When the specimen is stretched to an engineering strain of 0.09, an 80 ksi engineering stress is found. (a) What were the load and the change in gauge length values that were used to calculate the engineering stress and strain, respectively? (b) What are values of the true stress and the true strain? (c) Consider the true strain at this value of true stress. What portion of it is elastic and thus recovered upon unloading, and what portion of it is plastic?