Solution to Problem 678 | Midspan Deflection

$EI \,t_{A/B} = (Area_{AB}) \, \bar{X}_A$

$EI \,t_{A/B} = \frac{1}{2}(2.5)(3750)(\frac{5}{3}) - \frac{1}{2}(1.5)(1350)(2) - \frac{1}{2}(0.5)(300)(\frac{7}{3})$

$EI \,t_{A/B} = 5612.5 \, \text{ N}\cdot\text{m}^3$
 

$EI \, \delta_{midspan} = \frac{1}{2} (EI \, t_{A/B})$

$EI \, \delta_{midspan} = \frac{1}{2}(5612.5)$

$EI \, \delta_{midspan} = 2806.25 \, \text{ N}\cdot\text{m}^3$           answer