Design of Steel Bar Column <1sq, 6' Long; 30k psi Stress Limit

[john2516]

a steel bar 1 " sauare 6 ' long is to be used as a column.ends are free to rotate put may not be displaced stress is limited to 30,000 psi.
i believe my teacher expect conform code AISC.

 

[mathmate]

The answer depends on whether your teacher expects a design conform to codes, for example AISC, CISC, etc. It may be that he covered Euler buckling and simply the theoretical load is required. The context will determine the exact answer.
Meanwhile, it would be advantageous to Google the subject "Euler buckling" and do some research or studies. An article that seems to be quite adequate is:
http://en.wikipedia.org/wiki/Buckling
And the Euler buckling load/stress formulae are presented in the article.

 

[berkeman]

a steel bar 1 " sauare 6 ' long is to be used as a column.ends are free to rotate put may not be displaced stress is limited to 30,000 psi.

You need to show us the relevant equations and your attempt at a solution before we can help you on your question.