A composite material consists of a matrix and two kinds of reinforcements, fiber A and fiber $B.$ If ${}_{FA}=2\mathrm{.}8$GPa,${}_{FB}=3\mathrm{.}0$GPa, ${}_m=0\mathrm{.}07$GPa,$E_{fA}=390$GPa,$E_{fB}=150$GPa,$E_m=3\mathrm{.}5$GPa,$V_{fA}=40\%,V_{fB}=30\%$ and $Vm=30\%.$

A Calculate the longitudinal strength of the composite $(7)$

B$.$ Calculate the minimum strength of the composite in Q$2(6)$

Ci$.$ Sketch the stress$-$strain curves Q$2$A $(2\mathrm{.}5)$

Cii. Sketch the stress$-$strain curves for Q$2$B $(2\mathrm{.}5)$