1. The problem statement, all variables and given/known data Water enters a kidney through a tube at 10 mL/min. It exits through a 6-mm-diameter tube at 20 mm/s.What is the rate of change of mass of water in the kidney? 2. Relevant equations m=vpa q=va After conversions to meters V=.02 Q=.000167 A=(pi/4)*.006^2 = .0000282 3. The attempt at a solution dm/dt-Qp+VAp=0 dm/dt-(.000167)(999.1)+(.0000282)(.02)(999.1)=0 dm/dt=.165 kg/s Needless to say, thats not the right answer, but I can't figure out where I went wrong.