Solution to Problem 418 | Shear and Moment Diagrams

$M_{AB} = -20x \, \text{kN}\cdot\text{m}$
 
 
 

Segment BC:
$V_{BC} = -20 \, \text{kN}$

$M_{BC} = -20x + 80 \, \text{kN}\cdot\text{m}$
 
 
 

To draw the Shear Diagram:

1. V_AB and V_BC are equal and constant at -20 kN.

To draw the Moment Diagram:

1. M_AB = -20x is linear; when x = 0, M_AB = 0; when x = 4 m, M_AB = -80 kN·m.
2. M_BC = -20x + 80 is also linear; when x = 4 m, M_BC = 0; when x = 6 m, M_BC = -40 kN·m