sorry for the late reply
asdofindia - air was flow to the tube to mix the reactant in the tube then the 'flow out' is for air to flow out to atm and the outside flow rate is around 38 L/min. i just don't know which equation i should use to solve this problem.rcgldr- are you sure the darcy...
lets say if i have a test tube (diameter 3cm and height 30cm) seal with a rubber. in the test tube there 100ml of water = around 10 cm height. if air was flow into the test tube with flow rate around 20L/min, and after a few sec, the rubber was push out. in general i understand that the pressure...