For a column that is pinned at both ends, the critical buckling load can be calculated as, Pcr = π2 E I /L^2 where E is Young's modulus, I is the moment of inertia of the cross sectional area, and L is the length of the column. If E = 200 × 109 N/m^2, I = 21 × 106 mm^4, and L = 12 ft what is the critical buckling load in kip?