A spherical helium-filled balloon is used to lift a load of 5905 N (in addition to the weight of the helium). Suppose the density of the air is 1.24 kg/m3. Find the minumum necessary radius for the balloon. A 24.8 liter container is initially evacuated, and then 5.7 grams of water is placed in it. After a time, all the water evaporates, and the temperature is 115.8o C. Find the final pressure. A water tower, vented to the atmosphere, is drained by a pipe that extends to the ground. The top surface of the water in the tank is 15.7 m above the ground. If the valve in the drain pipe is closed, what is the absolute pressure in the drain pipe at ground level? Answer: 2.55E5 Pa If the valve is now open and the cross-sectional area of the drain pipe is 2.24E-2 m2, find the volume flow rate in the drain pipe. Assume that the water speed at the top of the water in the tank is negligible.