1. The problem statement, all variables and given/known data Please click on the link for the question. http://i1154.photobucket.com/albums/p526/cathy446/physicsquestion_zps49e16ab1.jpg Assume that air spreads out after coming out from the tube at 2. The speed over tube 1 is almost zero. 2. Relevant equations Knowledge problem on fluid dynamics Continuity equation A1v1 = A2v2 3. The attempt at a solution I know that the higher the liquid height of the tubes, the lower the air pressure. Higher flow speed also results in low pressure. So when the cross sectional area is large, the flow speed should be slow. Using this reasoning, my answer was h2 > h4 > h3 > h1 but that answer is wrong. Is something wrong with my logic? Any help would be appreciated.