$12$ As shown in the figure below, when a truck is moving to the left at $5$ m$/$s$,$ a stream of water with a cross$-$sectional area of $2$x$10-3$ m$2$ is sprayed toward the truck at $10$ liter$/$s$.$ At this time, what is the ratio of the vertical force to the horizontal force applied to the truck between points A and B$?$Where, cos C $=0\mathrm{.}8,$ sin C $=0\mathrm{.}6.$