4. Write the definitions for engineering stress, true stress, engineering strain, and true strain for loading along a single axis. A commercially pure copper wire originally 10.00 m long is pulled until its final length is 10.10 m. It is annealed, and then pulled again to a final length of 10.20 m. What is the engineering strain associated with each of the two steps in the process? What is the true strain for each step? What are the total engineering and true strains for the combined steps?