Conservation of mass: control volume approach question

AI Thread Summary
The discussion revolves around a control volume problem involving a brine solution entering a tank, leading to a first-order differential equation that the user struggles to solve. The user typically relies on an online solver but encounters a 'no solution' error, indicating a possible mistake in their approach. Other participants suggest reconsidering the problem statement and simplifying the calculations by focusing on the initial masses of salt and water instead of using differential equations. They recommend clarifying the problem details for better assistance. The conversation emphasizes the importance of correctly setting up the problem to find a solution.
George26
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Summary:: Control volume question that has a brine solution entering a tank and mass accumulates over time.

Hello, I'm currently struggling with a control volume approach question that has a brine solution entering a tank. I get to a point where I have a first order differential equation. I usually just plug them into an online solver but this one returns 'no solution'. I'm not too surprised and I think I'm making a mistake somewhere. It would be much appreciated if anybody can take a peak at my work and maybe push me into the right direction.

Thanks so much in advance.
 

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Hello @George26 ,
:welcome: !​
1616886165708.png


I don't understand what your differential equation is supposed to do.
Why not simply add 100 l of the one to 600 l of the other ?

Please type the problem statement next time.
I do find it questionable, but perhaps you are expected to assume some simple density relationship ?

##\ ##
 
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You don't need any differential equations.
What are the initial masses of salt and water?
How much of each has been added at time t?
 
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