An aluminum pipe column (alloy 6061-T6) that is fixed at the base and free at the top has outside diameter d2 = 80 mm and inside diameter d1 = 72 mm (see figure).
Determine the allowable axial load Pallow for each of the following lengths: L = 0.6 m, 0.8 m, 1.0 m, and 1.2 m.
(Convert the given data to USCS units, determine the required quantities, and then convert back to SI units.)