$3\mathrm{.}6\mathrm{.}9$ WP Water flows from a pressurized tank, through a

$6-$in$.-$diameter pipe, exits from a $2-$in$.-$diameter nozzle, and rises

$20$ ft above the nozzle, as shown in Fig. P$3\mathrm{.}6\mathrm{.}9.$ Determine the

pressure in the tank if the flow is steady, frictionless, and incom$-$

pressible.