1. The problem statement, all variables and given/known data A water tower is a familiar sight in many towns. The purpose of such a tower is to provide storage capacity and to provide sufficient pressure in the pipes that deliver the water to customers. A spherical reservoir contains 4.75 x 10^5 kg of water when full, and is 15m above the ground. The reservoir is vented to the atmosphere at the top. There are two houses connected to the tower, the first at ground level, and the second 7.2 m higher. For a full reservoir, find the gauge pressure that the water has at the faucet in each house. Ignore the diameter of the delivery pipes. Here is an image: http://img405.imageshack.us/img405/6920/p1187yc5.gif 2. Relevant equations P-Patm=pgh Pressure - atmospheric pressure = (water density * 9.8 * h) 3. The attempt at a solution I've gotten 1000 * 9.8 * 15m for the pressure in the tower. I've tried pgh + atmospheric pressure, and it doesn't work. I don't know what to do with the mass of the water in the tower. I am really stumped on this one. Thanks a million for any help.