A column fixed at both ends has a minimum radius of gyration r = 29.4 mm, cross-sectional area 3,230 mm, and length 1.94 m. It is made of a material whose compression stress-strain diagram may be approximated by a series of tangent-like segments as shown below. Determine the critical load. O (MPa) 350 280 210+ 140+ 70 0 1 E=46.7 (10) -E=175 (109) E=28 (109) 3 5 Et=14 (109) + 7 10. E