So the question asks: A circular wine barrel 75 cm in diameter will burst if the net upward force exerted on the top of the barrel is 643 N. A tube 1.0 cm in diameter extends into the barrel through a hole in the top. Initially the barrel is filled to the top and the tube is empty above that level. What weight of water must be poured into the tube to burst the barrel? I understand that the initially pressure in the tube is Patm before any water has been poured into it and that that pressure will later become P = Patm + Pwater(g)(h) but I can't seem to figure out how to answer the question. Any help would be appreciated!