Question $2$

$($a$)$ A pressure gauge at the top of the tank shown in Fig. $2$a$,$ registers a gauge pressure

of $-10\mathrm{.}0$kPa. The tank contains layers of oil, water and air as indicated. If piezometric

tubes are connected to the tank as shown, determine:

$($i$)$ The height $h_2.$

$($ii$)$ The total pressure in kPa exerted on the Oil $-$ Water interface.

$($b$)$ A rectangular gate hinged at its lower edge, is located as shown in Figure Q$2($b$).$ The

door is of length $8m$ and breadth $4m.$ The gate is inclined at an angle of $50$ to the

horizontal. Determine the hydrostatic force acting on the door for a water level as

shown in Figure Q$2($b$)$ and its location.