Answer:
156.0 ksi
Step-by-step explanation:
The formula of compressive strength is CS = F / A
where F is the force or load while A is the cross-sectional area
Given the inertia Ag = 35.1 in^4 , which is less than 40, the steel has a short column.
E = 29000 ksi
L = 12ft
r = 2.69 in
therefore;
CS = π^2 E / (kL^2/r)^2
= π^2 29000 / (0.8 x 12^2 / 2.69)^2
= 286292.756 / 1834.4089 = 156 ksi