$8-$ The rods $1,2,$ and $3$ shown below are welded together, mounted between two rigid walls and

subjected to the two forces shown at points $B$ and $C.$ The rods are all of the same length, namely

$L=1\mathrm{.}5m.$ Rods $1$ and $3$ are made from a material with $E=140{10}^{9}Pa.$ Rod $2$ is made from a

material with $E=80{10}^{9}Pa.$ The cross sections are given by: $A_1=A_3=50{10}^{3}m{m}^2$ and $A_2=$

$90{10}^{3}m{m}^2.$ Determine the displacement of points $B$ and $C.$