The square gate $AB(1\mathrm{.}8**1\mathrm{.}8ft)$ is held on the position shown by hinges along its top edge A and by a shear pin at B$.$ For a depth of water d $=3\mathrm{.}5ft.$ Determine the force exerted on the gate by the shear pin $($water denisty $=1\mathrm{.}94$ slug $\frac{?}{f{t}^3}$ and gravity $=32\mathrm{.}2f\frac{t}{se{c}^2}).$

Gate ABC in Fig $5$ has a fixed hinge line at $B$ and is $2m$ wide into the paper. The gate will open at $A$ to release water if the water depth is high enough. Compute the depth $h$ for which the gate will begin to open.