1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Extracting the question (D.E.)

  1. Feb 19, 2010 #1
    1. The problem statement, all variables and given/known data

    A tank is filled with 10 gal (gallons) of brine in which 30 lb of salt is dissolved.
    Brine having 2 lb of salt per gal enters the tank at the rate of 2 gal per min and the
    well-stirred mixture leaves at the rate of 3 gal per min.

    (a) Set up a differential equation fro the amount of salt at time t

    2. Relevant equations

    let S = be the salt leaves and enter
    V = volume of the tank

    3. The attempt at a solution

    im actually stuck with the question, at the

    "and the well-stirred mixture leaves at the rate of 3 gal per min."

    im terrible with english, so, someone give me clue
  2. jcsd
  3. Feb 19, 2010 #2
    It just means that you need to assume that as soon as the new brine enters the tank, the concentration of salt in the tank is uniform (perfectly mixed). So the D.E. would simply just be = (rate that salt enters tank) - (rate that salt leaves tank).
  4. Feb 19, 2010 #3
    owh yeaaaahhhhhhhhhhhhhhhhhhh, how come i miss the word "leaves"
    ok thank you very much
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - Extracting question Date
Vector components/coordinates question. Yesterday at 6:18 AM
Set notation question Mar 8, 2018
Extracting DE question Mar 14, 2010
Extracting a square root Jan 31, 2010
How to extract May 7, 2008