Problem $2$:

For the beams shown in Figure $2,$ using the work and energy method, and ignoring shear effects, determine:

$($a$)$ the deflection at point $C$ caused by the point load $P$ on the beam in Figure $2($a$).$

$($b$)$ the rotation at point $D$ due to the concentrated couple $M_o$ applied on the beam in Figure $2($b$).$