Proving that a vector field is conservative

And when you differentiate ##C_1## with respect to ##y##?In summary, the conversation is discussing how to determine if a vector field is conservative. The solution involves finding a potential function, represented as ##\phi##, by integrating the vector field ##F##. This involves integrating with respect to each variable and accounting for a constant of integration, ##C_1##. When differentiating ##\phi## with respect to ##y##, it is equal to the derivative of ##C_1## with respect to ##y##.
  • #1
JD_PM
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Homework Statement



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Homework Equations



$$F = \nabla \phi$$

The Attempt at a Solution



Let's focus on determining why this vector field is conservative. The answer is the following:

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[/B]
I get everything till it starts playing with the constant of integration once the straightforward differential equations have been solved.

May you explain how does it conclude that ##\phi (x, y, z)## is a potential for ##F##?

Thanks.
 

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  • #2
You want to find ##\phi## by integrating ##F##. You start by integrating with respect to ##x##, which tells you about the function form of ##\phi## with respect to ##x##, up to a constant ##C_1##, which is a constant wrt ##x## but can be a function of ##y## and ##z##. You then find how ##C_1## changes with ##y## by integrating over ##y##, and so on.
 
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  • #3
DrClaude said:
You want to find ##\phi## by integrating ##F##. You start by integrating with respect to ##x##, which tells you about the function form of ##\phi## with respect to ##x##, up to a constant ##C_1##, which is a constant wrt ##x## but can be a function of ##y## and ##z##. You then find how ##C_1## changes with ##y## by integrating over ##y##, and so on.

But I do not understand why ##\frac{\partial \phi}{\partial y} = \frac{\partial C_1}{\partial y}##
 
  • #4
At that point in the solution, what is ##\phi## equal to? What do you get when you differentiate it with respect to ##y##?
 
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1. What is a vector field?

A vector field is a mathematical concept used to describe the behavior of vector quantities, such as force or velocity, in a given space. It assigns a vector (magnitude and direction) to every point in the space.

2. How can I tell if a vector field is conservative?

A vector field is considered conservative if it satisfies the condition that the line integral around any closed path is equal to zero. This means that the work done by the vector field on a particle moving along a closed path is independent of the path taken.

3. What is the significance of a conservative vector field?

A conservative vector field has many practical applications in physics and engineering. It is used to model conservative forces, such as gravity and electrostatic forces, and can help determine the path of a particle under these forces.

4. How can I prove that a vector field is conservative?

To prove that a vector field is conservative, you can use the fundamental theorem of calculus. If the vector field can be expressed as the gradient of a scalar function, then it is conservative. Alternatively, you can also show that the line integral around any closed path is equal to zero.

5. Are all vector fields conservative?

No, not all vector fields are conservative. Only those that satisfy the condition that the line integral around any closed path is equal to zero are considered conservative. Non-conservative vector fields have a non-zero line integral around closed paths, indicating that the work done is path-dependent.

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