1. The problem statement, all variables and given/known data Here is the scenario: If I have a cylindrical tank containg 30 liters of a substance. I want to determing the pressure/ energy necessary to empty the tank in 55-60 seconds through a 1/2" diameter outlet. In other words how much gas would I need to introduce to the tank to completely empty in the given time frame. What equation would I need? Please tell me what other variables I would need and what equation? 2. Relevant equations Trying to determine 3. The attempt at a solution attempted to see if bernoulis equation could be utilized, but failed.