Question A$2[30$ marks $]$

$($a$)$ For the closed tank in Figure QA$2$a$,$ all fluids are at $20C,$ and the air space is pressurized. The net outward hydrostatic force on the $30-cm$ by $40-cm$ panel at the bottom of the water layer is found to be $8450$ N $.$

$($i$)$ Determine the pressure in the air space

$($ii$)$ Calculate the reading $h$ on the mercury manometer.

$[8]$

$[5]$