Prob $6.$ The beam shown below is made by attaching a C$-$channel on top of an I$-$beam. The beam has

dimensions as shown, note that the thickness of the C$-$channel is $10$ mm and the thickness of the l$-$beam is $20$

mm $.$ The screws have a maximum allowable shear force of $V_{\text{a}\text{l}\text{l}\text{o}\text{w}}=5\mathrm{.}5kN.$

$($A$)$ Determine the minimum spacing of the screws along the beam, if the maximum shear force in the beam

is $V=65kN$