Problem $3$: A column design load is given as $10,000lbf$ for a centrally loaded $15$ foot

long, structural steel $12$ in$.$ @ $30lb\frac{f}{f}t$ Channel $($Table A$-7).$ The material has a Yield

Strength of $36$ Ksi $,$ and a Modulus of Elasticity of $30{10}^6.$ Assume the column end$-$

condition constant $(C)=1\mathrm{.}2$ for buckling.

Required:

a$.(10)$ Determine if this column installation is considered an intermediate$-$length or a

long$-$length column problem $...$ will you use the Euler Equation or the Johnson

Equation to calculate your Critical Load $($Pcr$)?$ Why?

b$.(15)$ Determine the actual Buckling Factor of Safety of this installation.