2.3 Modeling with First-Order Equations

[@laninez7953]

So in the second term of the diff eq for the salt, you had a -4Q/160 term. Is the reason for the 160 because the volume going in is the volume going out, so no net increase of volume inside the tank?

[@msebastiznf]

Correct :)

[@laninez7953]

@@msebastiznf So essentially, this mixture problem is predicated on the fact that rate in = rate out. What if the problem had been changed to "the rate going in was 4 lb/gal and rate out was 2 lb/gal", will that technique work? P.S: I'm taking MATH 2552 fall 2020 semester as part of the mod-sim thread for CS.

[@laninez7953]

@@msebastiznf Are you also going to TA for MATH 2552 Fall 2020 semester?

[@msebastiznf]

La ninez I think you mean gal/min. It doesn’t matter how much salt comes in or comes out but yes I did on purpose choose that 4 gal/min of water comes in but also 4 gal/min leaves the tank as well. If we say 4 gal/min comes in but 2 gal/min leaves then the denominator would not just be 160 but rather 160 + 2t where the 2t term models the fact that we get an extra 2 gallons every min within the tank

[@msebastiznf]

La ninez Unfortunately no I graduated spring 2019 but I personally interviewed some of the new TAs and made sure to choose very good ones for GTs school of math. With their help, the faculty, and these videos hopefully you won’t need my in-person recitations :)

[@christopheregg-krings5717]

Thank you!!

[@msebastiznf]

No problem!