$1.$ For the rectangular gate, $3\mathrm{.}0$ m wide and $3\mathrm{.}0$ m high, shown in fig. $1,$ calculate:

a$)$ the hydrostatic force acting on the gate. $(282$ kN $)$

b$)$ the center of pressure from the free surface. $(3\mathrm{.}43$ m $)$

c$)$ the reaction force of the sill on the gate. $(163$ kN$)$

Fig. $1$

Fig. $2$

Fig. $3$