1. Not finding help here? Sign up for a free 30min 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!

Confusing DE word prob

  1. Sep 29, 2008 #1
    1. The problem statement, all variables and given/known data

    A tank contains 1000 gal of water in which 200 lb of salt is dissolved. 50 gal of brine, each gallon containing (1 + cos t) lb of dissolved salt, runs into the tank per minute. The mixture, kept uniform by stirring, runs out the same rate. Find the amount of salt in the tank at any time t.

    3. The attempt at a solution

    dc1/dt + dc2/ dt = 0

    Since dc1/ dt = - dc2/ dt then dc1/ dt + 50c/1000 = 0

    ∫dc/c = -∫1/20 dt

    Lower limit for dc/c is 200 and upper limit is c. Then, C = 200e^.05t

    But, no (1+cos(t)). Please help
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you help with the solution or looking for help too?

Similar Discussions: Confusing DE word prob
  1. Another prob question (Replies: 0)