The rectangular gate in the figure below is $5ft$ wide $($into the page$),$ is hinged at point $B,$ and rest against a smooth wall at point $A.$ Find the location of the vertical line of action $(y_{cp})$ in feet of the hydrostatic force. $I(\frac{?}{\text{b}\text{a}\text{r}})=\frac{b{h}^3}{12}$

$12\mathrm{.}58$

$10\mathrm{.}52$

$16\mathrm{.}12$

$8\mathrm{.}62$