A large tank holding water $($

$u=62\mathrm{.}4\frac{lb}{f}{t}^3)$ has a $3^{\text{'}}x{3}^{\text{'}}$ gate at the bottom of one of its walls, as shown.

Points $1,2,$ and $3,$ as labeled on the gate, are located at the top, middle, and bottom of the gate,

respectively. For the two possible depths of $2ft(h_1)$ and $4ft(h_2),$ calculate the hydrostatic pressure at each point, sketch the pressure prism acting on the gate, and determine the equivalent resultant force acting on the gate.