4. Using the data of Specimen 1 in Question 2 and Equations for true stress and true strain (see the presentation slides) generate a true stress-true strain plot for stainless steel. The equation of true stress expressed in terms of engineering strain becomes invalid past the point at which necking begins; therefore, measured diameters are given below for the last three data points, which should be used in true stress computations. Load, N Length, mm Diameter, mm 46,100 56.896 11.71 42,400 57.658 10.95 42,600 58.420 10.62 36,400 59.182 9.40 Note the equations for true stress and strain are: OT = F /Au Er = In ( ), or = (1 + E), and ET = In (1 + E)