Final answer:
The engineering ultimate tensile strength of 303 stainless steel, given the true stress at necking of 130,000 psi and a true strain of 0.45, can be approximated as roughly 130,000 psi.
Step-by-step explanation:
To calculate the engineering ultimate tensile strength of 303 stainless steel, we start with the given true stress at necking, which is 130,000 psi, and the true strain at necking, which is 0.45. Engineering stress is calculated by multiplying the true stress by the ratio of the original cross-sectional area (before deformation) to the current cross-sectional area (at necking). However, to calculate this without knowing the original and current cross-sectional areas, we use the approximation that the true stress approximately equals engineering stress up to the point of uniform elongation. Beyond that point, true stress continues to increase due to the decreasing cross-sectional area, whereas the engineering stress typically decreases after reaching the ultimate tensile strength (which occurs just before necking starts). Therefore, in this problem, we can consider the true stress at necking to be a good approximation of the engineering ultimate tensile strength unless the cross-sectional area drastically changes, which isn't mentioned in the question. Thus, the engineering ultimate tensile strength of 303 stainless steel in this scenario is approximately 130,000 psi.