A solid brass $[$E $=97$ GPa$]$ axial member is loaded and supported as shown. Segments $(1)$ and $(2)$ each have a diameter of $25$ mm and segment $(3)$ has a diameter of $13$ mm$.$ Assume L$1=1\mathrm{.}8$ m$,$ L$2=1\mathrm{.}2$ m$,$ L$3=1\mathrm{.}6$ m$,$ R $=36$ kN$,$ Q $=16$ kN$,$ and P $=26$ kN$.$

$1.$Determine the axial force in section $(2)$ in kN$.$

$2.$Determine the axial deformation of section $(2).$

$3.$Determine the axial force in section $(1)$ and section $(3).$

$4.$Determine the deflection of joint D $($positive if downward$)$ with respect to the fixed support at A$.$

$5.$ Determine the maximum normal stress in the entire axial member. Give answer in MPa.