A manometer is used for the pressure measurement in a closed tank. The three fluids $$f1,f2$$ and $$f3$$ have specific weights $$\gamma ,$$ $$2\gamma ,$$ and $$0.5\gamma ,$$, respectively. The schematic arrangement with manometric readings and other dimensions are shown in the Figure. In order to ensure zero gauge pressure in the tank at the mid-height level $$(h/2),$$ the height of the tank $$h$$ (in $$m$$) is _________________.

A $$2m \times 2m$$ square operating in a vertical wall is covered with a metalic plate of the same dimensions as shown in the figure below. Consider the acceleration due to gravity to be $$10.0\,\,m/{s^2}.$$ The force (in kN) exerted by water on the plate is _____________.