Problem $2$:

The beam shown in Figure $2$ is made of wood with a $75150mm$ rectangular cross section and $E=13$GPa. Use

Castigliano's Theorem to determine:

$($a$)$ the vertical displacement at point $C.$

$($b$)$ the vertical displacement at point $D.$

$($c$)$ the slope at point $C.$

Figure $2$