A square wood platform, 8ft x 8ft in area, rests on masonry walls (see figure). The deck of the platform is constructed of 2in nominal thickness tongue-and-groove planks (actual thickness 1.5in; see Appendix F) supported on two 8-ft long beams. The beams have 4in x 6in nominal dimensions (actual dimensions 3.5in x 5.5in).
The planks are designed to support uniformly distributed load w (lb /ft2) acting over the entire top surface of the platform. The allowable bending stress for the planks is 2400psi and the allowable shear stress is 100psi. When analyzing the planks, disregard their weights and assume that their reactions are uniformly distributed over the top surfaces of the supporting beams.
(a) Determine the allowable platform load w1 (lb/ft2) based upon the bending stress in the planks.
(b) Determine the allowable platform load w2 (lb/ft2) based upon the shear stress in the planks.
(c) Which of the preceding values becomes the allowable load w allow on the platform?

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8 ft 8 ft wall