The aluminum column has a rectangular cross section and supports an axial load P. The base of the column is fixed. The support at the top allows rotation of the column in the x-y plane (i. e., bending about the strong axis) but prevents rotation in the x-z plane (i. e., bending about the weak axis).

(a) Determine the critical buckling load of the column for the following parameters: L = 54 in., b = 0.4 in., h = 0.8 in., and E = 10100 ksi.
(b) Determine the ratio b/h for which the critical buckling load about both the strong and weak axes is the same.