n open tank (diameter D1 = 4 m) with a long drain hose of diameter D2 = 5 cm is filled with fluid to height H = 5 m. The fluid (density = 1000 kg/m 3; viscosity = 10 mPas), is kept in the tank by plugging the drain. The pressure around the tank and the drain hose is atmospheric. Viscous losses can be neglected. Acceleration due to gravity is g = 10 m/s2. A) Determine the minimum force required to prevent the plug from popping out. B) Ignoring viscous losses (frictionless drain), determine the velocity vout and mass flow rate m of liquid leaving the drain when the plug is pulled. C) As liquid drains from the tank, the height of liquid in the tank slowly decreases. Derive an equation for the rate dH/dt at which the height changes. D) Determine the time required to empty half of the tank