$2\mathrm{.}12$ In Figure $2\mathrm{.}16,$ the weight of the upper piston $(W_1)$ is $85$ pounds $(39kg)$

and has a surface area of $113i{n}^2(729c{m}^2).$ The weight $(W_2)$ of the lower

piston is $14$ pounds $(6$ kg $)$ and has a surface area of $12\mathrm{.}6i{n}^2(81c{m}^2).$ If

the liquid in the hydraulic system is an oil with a specific gravity of $0\mathrm{.}90,$

what force $(F)$ will be required to attain a state of equilibrium?

Figure $2\mathrm{.}16$ Illustration for Exercise $2\mathrm{.}12$

english system NOT INTERNATIONL