Polylactic acid $($PLA$)$ is used to $3$D print a small truss. One of the truss members has a length of $50$ mm with a

rectangular cross section of $3mm5mm.$ Assume that the truss member is supported in a way such that the

end condition factor $k$ is $1\mathrm{.}0($both ends of the member are pinned$).$ If the elastic modulus of the truss material is

$3,000$MPa $($or $3$ GPa $),$ then determine the following:

a$.$ The buckling load if the member buckles in the direction of the $3$ mm thickness. Note that when

computing the moment of inertia, b is $5$ mm and h is