Shear stress in a standard steel shape

Constructing the shear diagram

Considering the segment
from x = 0 m to x = 0 m

     area under load
                diagram =   0.00 kN
         concentrated
                   forces = +2.00 kN
     total shear force
                  change = +2.00 kN

              at x = 0 m,    V =      0.00 kN
        total shear force
                     change   =    +2.00 kN
               at x = 0 m,   V =    +2.00 kN