Q$\mathrm{.}7(10$ points$)$

Engineering stress$-$strain data from a tension test on gray cast iron are given in Table $3.$

The diameter before testing was $10$ mm $,$ and after fracture it was $9\mathrm{.}5$ mm $.$

$($a$)$ Determine the following: tangent modulus, $\backslash (0\mathrm{.}2\backslash \%\backslash )$ offset yield strength, ultimate tensile strength, percent elongation, and percent reduction in area.

$($b$)$ How do these properties differ from the corresponding values for ductile cast iron in listed below.

Explain why these two cast irons have contrasting tensile behavior.

Table $3$