1. A slender vertical bar AB with pinned ends and length L is held between immovable supports. What increase ?T in the temperature of the bar will produce buckling?
2. A W2 × 87 structural steel column has a length of 12 ft. (Look up the geometric properties of the W2 × 87 cross section.) If its bottom end is fixed, while its top is free, and it is subjected to an axial load of P = 380 kip, determine the safety factor with respect to buckling