How do I use F and the divergence theorem to find the flux and plot it?

Summary: In summary, the conversation discusses a homework problem involving plugging F into the divergence theorem and plotting it for specified function values. The equation for the divergence of an arbitrary vector in spherical coordinates is mentioned, and suggestions are given for how to approach the problem, including using spherical coordinates and integrating over the surface of a sphere for the flux.
  • #1
renegade05
52
0

Homework Statement



Capture.JPG


Homework Equations



∇.F(r)

The Attempt at a Solution



I keep trying to plug F into the divergence theorem but end up with very ugly answers that I know are not right.

Is there a simple way to do this question? Also, how the heck would I plot this for for the specified function values! thanks! help with the flux would be appreciated to.
 
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  • #2
Your starting equation should be the equation for the divergence of an arbitrary vector in spherical coordinates. What is that equation?

Chet
 
  • #3
Can you show us your approach and what you did to get ugly answers for the divergence?

Did you use spherical coordinates? and the spherical variant of the divergence operator?

http://en.wikipedia.org/wiki/Del_in_cylindrical_and_spherical_coordinates

For plotting you could use MATLAB or FreeMat (a free clone of MATLAB).

For the flux you have to integrate over the whole surface of the sphere. If you recall the surface of a sphere
is 4*pi*r^2 which might help you with the eventual solution.

http://en.wikipedia.org/wiki/Sphere
 

FAQ: How do I use F and the divergence theorem to find the flux and plot it?

1. What is the concept of divergence in relation to F and plot?

Divergence refers to the rate at which a vector field, represented by F, is spreading out or converging at a specific point on a plot. It can also be thought of as the measure of the flow of a vector field away from a given point.

2. How is divergence calculated for a given function?

Divergence can be calculated by taking the dot product of the gradient of a vector field and the vector field itself. This can be represented mathematically as div(F) = ∇ ⋅ F, where ∇ is the gradient operator and ⋅ represents the dot product.

3. What does a positive or negative divergence value indicate?

A positive divergence value indicates that the vector field is spreading out or diverging at a given point, while a negative divergence value indicates that the vector field is converging at that point.

4. How does divergence relate to the behavior of a vector field?

Divergence is a measure of the flow of a vector field, so it can tell us how the vector field is behaving at a given point. If the divergence is positive, the vector field is expanding or moving away from the point. If the divergence is negative, the vector field is converging or moving towards the point.

5. Can divergence be visualized on a plot?

Yes, divergence can be visualized on a plot by using vector field arrows that represent the direction and magnitude of the flow at different points. The spacing between the arrows can also indicate the rate of divergence at each point, with closer spacing indicating higher divergence and vice versa.

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