Q: When a person inhales, air moves down the bronchus (windpipe) at 15 cm/s. The average flow speed doubles through a constriction in the bronchus. Assuming incrompressible flow, determine the pressure drop in the constriction. OK what confuses me is that I thought that if you decrease the width of a passage (e.g cholesterol in an artery) you increase pressure. However this asks for pressure DROP in constriction??? Equation I thought would be P = F/A, but not real sure at all. Please help me get the ball rolling!