Question

A tank initially contains 120 L of pure water. A salt mixture containing a concentration of 1.5 g/L enters the tank at a rate of 2 L/min, and the well-stirred mixture leaves the tank at the same rate. Find an expression for the amount of salt in the tank at any time t. Also, find the limiting amount of salt in the tank as t +0. (10 points)

Answer 1

- = da de xin ub =39mm t년 10 xin 느 mini X2.. 은 L se out X2 1 즌은 g (min min > dx. =3른7 de vios +gimt - a outt V2 =) V - 120 + 2 2 = (20 da xt - E = 카이 - 3 - . 60 OT) C da dei - 3 즈 to) = 0, 60 da =) t = 3 (liman of e) de 60 Heue dt 는 0 p() 는, () = 3 s preide Nee Se alejdete e x(t) - A

settsdete -> alt) = T- toot bot dot · tc YGO 180 tcetoot [ e 3 بع 444) = Q = (03X :: - 180tcco ) C-180 .: Melt) =180-1800 e do ၂) Male Attoo , alt) =180