$1.$ Consider a W$18$x$130$ column with pinned end conditions.

a$.$ Using the equations from Chapter $\backslash ($ E $\backslash )$ of the MSC$,$ plot the critical stress, Fcr $($along with the $\backslash (\backslash$mathbf$\{$y$\}\backslash )-$axis$)$ vs$.$ Lc$/$r $($along with the $\backslash (\backslash$mathbf$\{$x$\}\backslash )-$axis, using a range from $0$ to $250)$ for the following three cases:

Note: put all three curves on the same graph.

$1.$ The theoretical "Euler" buckling stress.

$2.$ Buckling stress for material with a yield strength, $\backslash (\backslash$mathrm$\{$F$\}\_\{\backslash$mathrm$\{$y$\}\}\backslash ),$ of $36$ ksi $.$

$3.$ Buckling stress for material with a yield strength, $\backslash (\backslash$mathrm$\{$F$\}\_\{\backslash$mathrm$\{$y$\}\}\backslash ),$ of $50$ ksi $.$

Use MathCAD or Excel to calculate the results and plot the graphs. Be sure to include your calculations and a table of your data points used to make your plot.