Answer the folloing questions:

A$)$

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If $P=15kN,$ determine the average shear stress in the pins at $A,B,$ and $C.$ All pins are in double shear, and each has a diameter of $18mm.$

B$)$ Determine the size of square bearing plates $A^{\text{'}}$ and Required to support the loading. Take $P=1\mathrm{.}5$ kip. Dimension the plates to the nearest $\frac{1}{2}$ in$.$ The reactions at the supports are vertical and the allowable bearing stress for the plates is $($ b$)$ allow $=400$ psi.