I have no idea where even to start with this one, so anything will help!
A tank initially contains 60 gal of pure water. Brine containing 1 lb of salt per gallon enters the tank and 2 gal/min and the (perfectly mixed) solution leaves the tank at 3 gal/min; thus tthe tank is empty after exactly one hour. (a) Find the amount of salt in the tank after t minutes. (b) What is the maximum amount of salt ever in the tank?
Sep 21st 2009, 01:45 PM
simply let y be the amount of salt in the tank at time t
dy/dt = salt in -salt out
the volume of fluid in the tank is v(t) = 60 -t gals
How would one go about solving part b? I have a figured out, but part b is stumping me. I tried maximizing the function, but the solution is not in agreement with the solutions manual...ANy help from here would be appreciated!
Sep 21st 2009, 04:10 PM
Sep 21st 2009, 04:31 PM
Thank You Very Much!!!
May 17th 2010, 03:30 AM
i think there's something wrong, i think it should be dy/dt +3y/(60-t) = 2