Figure $3\mathrm{.}4$: The circular gate.

Figure $3\mathrm{.}4$ shows a schematic of a vertical, circular gate with diameter $1\mathrm{.}0m,$ with its centre

$3\mathrm{.}4m$ below the water surface. Find the resultant thrust and its depth below the water surface.

Calculate

The water thrust : N

Moment of inertia : Nm$^2$

First moment : N

Elevation of the thrust : m