고체역학 (Beer) — Analysis and Design of Beams for Bending: Problem 5.154

5.154 Determine (a) the distance \( a \) for which the absolute value of the bending moment in the beam is as small as possible, (b) the corresponding maximum normal stress due to bending. (See hint of Prob. 5.27.) Given from Fig. P5.154: Beam length segment \( AC = a \), \( CD = 1.5 \text{ ft} \), \( DE = 1.2 \text{ ft} \), \( EB = 0.9 \text{ ft} \). Loads: \( 0.8 \text{ kips} \) at \( A \), \( 1.2 \text{ kips} \) at \( D \), \( 1.2 \text{ kips} \) at \( E \). Supports at \( C \) and \( B \). Beam section: \( \text{S3} \times 5.7 \).