Figures below present indentation diagram $($ P vs$.$ h $)$ obtained on fused silica and aluminum and

reproduced from the classic paper by W$.$ C$.$ Oliver and G$.$ M$.$ Pharr, J$.$ Mater. Res. $1992,$ which

you studied for the lab No$\mathrm{.}6.$ Assume perfect Berkovich tip, the geometric indenter constant $lon$

equal to $0\mathrm{.}75,$ and indenter properties $E_i=1141$GPa and $v_i=0\mathrm{.}07.$ Based on this experimental

data determine the hardness, $H,$ and elastic modulus, E$,$ of fused silica. Poisson's ratio of fussed

silica equals $0\mathrm{.}17,$ and for aluminum $0\mathrm{.}347.$ Express your final values in GPa. Please, show your

work in step$-$by$-$step fashion.