$4-$ Given: $D=15m,d=3m,$ radius of hole $=0\mathrm{.}015m$

A$)$ Find the frictional force $($Pressure$)$ needed by the plug.

B$)$ Find the water volume exiting in $8$ hours, when water flowing out of the hole.

C$)$ Find the kind of flow in the hole for given:

$=0\mathrm{.}0012k\frac{g}{m}.s,=1000k\frac{g}{m^3}$

$(20$ pts$.)$