(adsbygoogle = window.adsbygoogle || []).push({}); [SOLVED] Classic watertank equation

I'm having trouble with a variant of the classic watertank equation. The data is as follows.

A tank contains 300 liters of saline water, containing a total of 1800 grams of salt. Through an inlet, saline water containing 5 grams/liter is pumped in at a speed of 2 liters/minute. The well-mixed solution is pumped out at a speed of 3 liters/minute. Compute the quantity of salt, in grams, after 100 minutes.

Here's my attempt at solving this:

[tex]

V(t)=300-t

[/tex]

[tex]

\frac{dS}{dt}=10t-3\frac{S}{V}

[/tex]

[tex]

S(0)=1800

[/tex]

Running it in the ODE Analyzer in MAPLE got me [tex]S(100)\approx33867[/tex], which isn't the solution. Can anyone spot what I've done wrong?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Classic watertank equation

**Physics Forums | Science Articles, Homework Help, Discussion**