Problem $11-2$: Determine the critical load for a pinned$-$end column made of a circular bar of SAE $1020$ hot$-$rolled steel $($Refer to Appendix A$-10).$ The diameter of the bar is $20$ mm $,$ and its length is $350$ mm $.$

a$)$ Calculate slenderness ratio $=K\frac{L_E}{r}=$

b$)$ Transition Slenderness Ratio $=C_C=$

c$)$ Is this column classified as "long" or "short"? $$

d$)$ Critical Buckling Load $-P_{cr}=$ kN