$(6)$ This cross$-$section is doubly$-$symmetric, but the $x-$axis moment of inertia is about four times larger than the

$y-$axis moment of inertia.

What is the critical buckling load, $P_{cr},$ for this pin$-$pin

column? The length of the column is $60$ feet, and it is

made of steel $(E=29,000$ksi$).$ You can use either

equation for the critical buckling load.

Given:

$I_x=10\mathrm{.}56i{n}^4$

$I_y=2\mathrm{.}565i{n}^4$