Question 9
Which rectangular timber beam section has the greatest ideal bending capacity? AI reconstruction: all beams have the same wood strength, span, supports and vertical loading; compare bending failure only about the horizontal centroidal axis, ignoring defects, shear, buckling and self-weight differences. Width × vertical height, in inches: A 3×4½; B 4×4; C 2½×5; D 2×6; E 1¼×7.
