I am trying to do a mixing problem here and I don't know how to set up the problem....
Brine containing 1 lb/gal of salt is poured at 1 gal/min into a tank that initially contained 100 gallons of fresh water. The mixture is stirred constantly and is drained of at 1 gal/min.
What is the actual amount of salt in the tank at time , t ?
I was thinking
dA/dt = (concentration in )(rate of waterflow) - (concentration out )(rate of water exiting)
and have it in the formula
(0)(1)-(A(t)/100)(1) dA/dt = -A/100 * 1 dA/dt = -A/ 0.01 integral of 1 / A da = integral of -1/ 0.01 dt ln|A| = 1/ 0.01t + C
I don't how to go from here...am I on the right track ?