Question $5$: Material Properties $[25$ Marks$](10$ and $15$ Marks each$)$

a$)$ Draw the stress$-$strain curve. What are the various regions on a stress$-$strain curve?

b$)$ A metal rod $2\mathrm{.}0$ m long has a cross$-$sectional area of $0\mathrm{.}30c{m}^2.$ The rod is now hung by one end from a support structure, and a $550$ kg milling machine is hung from the rod's lower end. Determine the stress, strain, and the elongation of the rod.