$\Sigma M_A = 0$
$6R_2 = 2(60) + 7(30)$
$R_2 = 55 \, \text{kN}$
$\Sigma M_C = 0$
$6R_1 + 1(30) = 4(60)$
$R_1 = 35 \, \text{kN}$
To draw the Shear Diagram:
- VA = R1 = 35 kN
- VB = VA + Area in load diagram - 60 kN
VB = 35 + 0 - 60 = -25 kN
- VC = VB + area in load diagram + R2
VC = -25 + 0 + 55 = 30 kN
- VD = VC + Area in load diagram - 30 kN
VD = 30 + 0 - 30 = 0
To draw the Moment Diagram:
- MA = 0
- MB = MA + Area in shear diagram
MB = 0 + 35(2) = 70 kN·m
- MC = MB + Area in shear diagram
MC = 70 - 25(4) = -30 kN·m
- MD = MC + Area in shear diagram
MD = -30 + 30(1) = 0