For the three$-$bar assemblage shown in Figure $3-4,$ determine $($a$)$ the global stiffness matrix, $($b$)$ the displacements of nodes $2$ and $3,$ and $($c$)$ the reactions at nodes $1$ and $4.$ A force of $3000$ lb is applied in the $x$ direction at node $2.$ The length of each element is $30$ in $.$ Let $E=30{10}^6$ and $A=1i{n}^2$ for elements $1$ and $2,$ and let $E=15{10}^6$ psi and $A=2i{n}^2$ for element $3.$ Nodes $1$ and $4$ are fixed.

$2.$

Problem

Determine the support reaction forces at the two ends of the bar shown above, given the following:

$P=6\mathrm{.}0{10}^{4}N,E=2\mathrm{.}0{10}^4\frac{N}{m}{m}^2$

$A=250m{m}^2,L=150mm,=1\mathrm{.}2mm$