Conservation of mass: control volume approach question

In summary, the conversation is about a control volume question involving a brine solution entering a tank and mass accumulating over time. The person is struggling with a first order differential equation and is asking for help in finding the solution. They are also questioning the need for a differential equation and wondering about the initial masses and amounts added over time.
  • #1
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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  • #2
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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  • #3
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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FAQ: Conservation of mass: control volume approach question

What is the conservation of mass?

The conservation of mass is a fundamental law in physics that states that mass cannot be created or destroyed, only transformed from one form to another.

What is the control volume approach in conservation of mass?

The control volume approach is a method used to analyze the flow of mass through a system or region. It involves drawing a boundary around a specific area and tracking the mass entering and exiting that boundary to determine the overall mass balance.

How is the conservation of mass applied in real-world scenarios?

The conservation of mass is applied in various fields, such as chemistry, physics, and environmental science, to understand and predict the behavior of matter in different systems. It is used to analyze chemical reactions, study the movement of fluids, and monitor the impact of human activities on the environment.

What are some limitations of the conservation of mass principle?

While the conservation of mass is a fundamental law, it does have some limitations. It assumes that mass is continuous and does not account for the possibility of mass being created or destroyed on a small scale. It also does not consider the effects of relativity and quantum mechanics.

How does the conservation of mass relate to other conservation laws?

The conservation of mass is closely related to other conservation laws, such as the conservation of energy and the conservation of momentum. These laws are interconnected and often used together to analyze physical systems. The conservation of mass is also a special case of the more general principle of conservation of mass-energy, which takes into account the conversion of mass into energy and vice versa.

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