A hollow circular post ABC (see figure) supports a load Pi 1800 lb acting at the top. A second load P2 is uniformly distributed around the cap plate at B. The diameters and thicknesses of the lower parts of the post are dдB = 1.2 in., t4B = 0.5 in., dB = 2.25 in., and tд0 = 0.37 in., respectively. AB dAB dpc fac upper and (a) Calculate the normal stress AB in the upper part of the post. Round your answer to the nearest whole number. σAB = psi (b) If it is desired that the lower part of the post have the same compressive stress as the upper part, what should be the magnitude of the load Pg? Round your answer to the nearest whole number. P₂ = lb (c) If P₁ remains at 1800 lb and P2 is now set at 2250 lb, what new thickness of BC will result in the same compressive stress in both parts? Round your answer to three decimal places. tBC= inches