The vertical shear force acting on the I$-$section shown is $100kN.$

Determine:

a$.$ The shear stress acting at the neutral axis on the

cross section.

b$.$ The shear stress acting at a point $40mm$ below the

neutral axis.

c$.$ The shear stress acting at a point just above the

bottom flange.

$I_{NA}=45\mathrm{.}87{10}^{6}m{m}^4$