# Thread: Tank rate Flow Pollution

1. ## Tank rate Flow Pollution

Hi, I am having trouble solving this problem:

A 1000 gallon holding tank that catches runoff from some chemical process
initially has 800 gallons of water with 2 ounces of pollution dissolved in it.
Polluted water flows into the tank at a rate of 3 gal/hr and contains 5 ounces/gal of
pollution in it. A well mixed solution leaves the tank at 3 gal/hr as well. When the
amount of pollution reaches 500 ounces the inflow of polluted water is cut off and
fresh water will enter the tank at a decreased rate of 2 gallons while the outflow is
increased to 4 gal.hr. Determine the amount of pollution in the tank at any time t.

This site has the answer but does not really give any details. It is the 2nd example.
Pauls Online Notes : Differential Equations - Modeling with First Order DE's

Thank you very much for your time in helping me.

2. Originally Posted by MathHelps
Hi, I am having trouble solving this problem:

A 1000 gallon holding tank that catches runoff from some chemical process
initially has 800 gallons of water with 2 ounces of pollution dissolved in it.
Polluted water flows into the tank at a rate of 3 gal/hr and contains 5 ounces/gal of
pollution in it. A well mixed solution leaves the tank at 3 gal/hr as well. When the
amount of pollution reaches 500 ounces the inflow of polluted water is cut off and
fresh water will enter the tank at a decreased rate of 2 gallons while the outflow is
increased to 4 gal.hr. Determine the amount of pollution in the tank at any time t.

This site has the answer but does not really give any details. It is the 2nd example.
Pauls Online Notes : Differential Equations - Modeling with First Order DE's

Thank you very much for your time in helping me.
The link seems pretty comprehensive, what in particular do you find difficult there?

CB