Problem $03$

A $3-$ft$-$long gate is closed at $45$ with respect to the interface between water and oil. The width of

the gate $($into the paper$)$ is $5$ ft $.$ The specific gravity of oil is $0\mathrm{.}8,$ where specific gravity is defined as

the ratio of density with respect to the density of water at the same temperature. Use the standard

value for graviational acceleration. ${}_{\text{w}\text{a}\text{t}\text{e}\text{r}}=1\mathrm{.}94$slu$\frac{g}{f}{t}^3.$

$($a$)$ Using the manometer reading, estimate the absolute pressure at the top of the tank $($on the

inside$).$

$($b$)$ Evaluate the location of centroid and center of pressure for the gate.

$($c$)$ Calculate the minimum weight of the gate so that it is kept closed.