Prob $7.$ The beam shown below is made by attaching two C$-$channels together. The beam has dimensions

as shown, note that the thickness of the C$-$channel is $20$ mm $.$ The screws are spaced $200$ mm apart along the

length of the beam.

$($A$)$ Determine the largest allowable shear force in the beam if the allowable shear force of the bolts is

Vallow$=7\mathrm{.}5$Kn