Additional Problem $2$:

The beam shown below consists of an American Standard $($S$)$ section with a plate $(16mm$ thick by $200-mm$ wide$)$ bolted to the top flange and another bolted to the bottom, using $18-mm$ diameter bolts spaced longitudinally every $120mm$ as shown in the crosssection below. If the allowable shear stress in a bolt is $85$MPa, calculate the largest vertical shear force allowed on the beam cross$-$section.