A rectangular tank with depth W $($into the page$)$ is filled with water, and has a hinged rectangular door on one side as shown. The top of the door is at depth h$\_1,$ and the bottom of the door is at depth h$\_2.$ A reaction force F$\_$R is applied to the top of the door in order to hold the door in place. Calculate F$\_$R assuming h$\_1=1$m$,$ h$\_2=2\mathrm{.}5$m$,$ and W $=4$m$.$