First of all, thanks to all the PF mentors out here, especially TSny and pgardn, who have made physics doable and are helping me accomplish my dreams! Even when putting in the work its not easy to get all this stuff! 1. The problem statement, all variables and given/known data A large water tank has an inlet pipe and an outlet pipe. The inlet pipe has a diameter of 3 cm and is 1 m above the bottom of the tank. The outlet pipe has a diameter of 9 cm and is 7 m above the bottom of the tank. A volume of 0.6 m3 of water enters the tank every three minutes at a gauge pressure of 1 atm. (a) What is the velocity of the water in the outlet pipe? 2. Relevant equations A1V1=A2V2 DV/Dt=AV (for both) 3. The attempt at a solution I've done three practice problems, and gotten them all right. The difference between those and this one, is that the volume of water enters over three minutes, instead of one. So I think that's part of where I'm messing up. My method: Knowing DV/Dt = Av, I plugged and chugged: .6/180=(.045^2)pi*v1=> v1=.524 m/s. This exact method worked before, but for this problem, the answer is .589 m/s. Does anyone see where I messed up?