Segment AB:
$V_{AB} = -20 \, \text{kN}$
$M_{AB} = -20x \, \text{kN}\cdot\text{m}$
Segment BC:
$V_{BC} = -20 \, \text{kN}$
$M_{BC} = -20x + 80 \, \text{kN}\cdot\text{m}$
To draw the Shear Diagram:
- V_{AB} and V_{BC} are equal and constant at -20 kN.
To draw the Moment Diagram:
- M_{AB} = -20x is linear; when x = 0, M_{AB} = 0; when x = 4 m, M_{AB} = -80 kN·m.
- M_{BC} = -20x + 80 is also linear; when x = 4 m, M_{BC} = 0; when x = 6 m, M_{BC} = -40 kN·m