고체역학 (Gere) — Shear Forces and Bending Moments: Problem 4.3-7

4.3-7 The beam $ABCD$ shown in the figure has overhangs at each end and carries a uniform load of intensity $q$ (Fig. a). For what ratio $b/L$ will the bending moment at the midpoint of the beam be zero? Repeat for a triangular load with peak intensity $q_0$ at $L/2$ (Fig. b).