Solve Problems # $5-1,5-3,5-4$

Determine the critical buckling load for each of the columns, using the Euler equation. $E=29,000$ ksi. Proportional limit $=36,000$ psi. Assume simple ends and maximum permissible $\frac{L}{r}=200.$

$5-1.$ A solid round bar of $1\frac{1}{4}$ in diameter:

a$.L=4ft0$ in $($Ans$.14\mathrm{.}89$kips $)$

b$.L=2ft3$ in $($Ans$.$ Euler equation not applicable, $F_c$ exceeds proportional limit

c$.L=6ft6$ in $($Ans$.$ Euler equation not applicable, $\frac{L}{r}$ exceeds $200)$

$5-3.$ A W$1250,L=20ft0$ in$.($Ans$.278\mathrm{.}7k)$

$5-4.$ The four $-L44\frac{1}{4}$ shown for $L=40ft0in.$

$5-5.($Ans$.212$ k LRFD; $14$