$2)$ The beam, shown in Figure $9\mathrm{.}3,$ contains a pin at point C and a roller at point A$.$ a$)$ Draw the free body diagram of the beam. b$)$ Determine the support reactions at points A and C$.($Marks $3)$ c$)$ Determine the normal force, shear force and bending moment at point D$.$

$*$The $20$ kN is applied midway between member A$3$

Figure $9\mathrm{.}3$