A wood beam 8 in. wide and 12 in. deep (nominal dimensions) is reinforced on top and bottom by 0.25-in.-thick steel plates (see figure part a).
(a) Find the allowable bending moment Mmax about the z axis if the allowable stress in the wood is 1,100 psi and in the steel is 15,000 psi. (Assume that the ratio of the moduli of elasticity of steel and wood is 20.)
(b) Compare the moment capacity of the beam in part a with that shown in the figure part b which has two 4 in. x 12 in. joists (nominal dimensions) attached to a 1/4 in. x 11.0 in. steel plate.

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in. X 11.0 in steel plate 4 3.5 in 0.25 in לך4x12 0.25 in joists