Verify Divergence Theorem for V = xy i − y^2 j + z k and Enclosed Surface

In summary, the divergence theorem was used to verify the function V = xy i − y^2 j + z k and the surface enclosed by three parts. The LHS was solved and the answer was found to be a*Pi. On the RHS, the integral was split into three surfaces and for (i) and (ii), the integral was found to be 0. For (iii), the integral was found to be ((1-a^2)(-x^2 y +y^3 + x^2 +y^2) +a^2)/Sqrt(a^2+(1-a^2)(x^2+y^2) dxdy between -1 and 1 for x and y. However
  • #1
nestleeng
1
0

Homework Statement


Verify the divergence theorem for the function
V = xy i − y^2 j + z k
and the surface enclosed by the three parts
(i) z = 0, s < 1, s^2 = x^2 + y^2,
(ii) s = 1, 0 ≤ z ≤ 1 and
(iii) z^2 = a^2 + (1 − a^2)s^2, 1 ≤ z ≤ a, a > 1.

Homework Equations


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[PLAIN]https://upload.wikimedia.org/math/7/b/7/7b759968274f2f43cfaab3ce5672da74.png[PLAIN]https://upload.wikimedia.org/math/a/b/9/ab9fd5a4aaa36e402c98cbd36af3a70d.png

Divergence theorem, although on the RHS I put vector DS = nDS.

The Attempt at a Solution


So I solved the LHS and got the answer to be a*Pi

on the RHS, splitting the 3 surfaces,
(i) got 0 for integral
(ii) got 0 for integral
(iii) staying in cartesians, I have to integrate ((1-a^2)(-x^2 y +y^3 + x^2 +y^2) +a^2)/Sqrt(a^2+(1-a^2)(x^2+y^2) dxdy between -1 and 1 for x and y which even Wolfram can't do.

Spent hours on this please help.
 
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  • #2
You haven't really said much about what you did. What did you get for [itex]\nabla\cdot\vec{V}[/itex]? What are s and a? Constants? Then "(ii) s= 1, [itex]0\le z\le 1[/itex]" makes no sense.
 

1. What is the Divergence Theorem?

The Divergence Theorem is a mathematical theorem that relates the flow of a vector field through a closed surface to the volume of the region enclosed by the surface. It is also known as Gauss's Theorem or Green's Theorem in three dimensions.

2. How is the Divergence Theorem used in scientific research?

The Divergence Theorem is used in many fields of science, including physics, engineering, and fluid mechanics. It allows for the calculation of flux, or flow, of a vector field through a closed surface, which has many practical applications such as in fluid dynamics and electromagnetism.

3. Can you explain the mathematical formula for the Divergence Theorem?

The mathematical formula for the Divergence Theorem is: ∫∫S F · dA = ∭V div(F) dV, where F is a vector field, S is a closed surface, and V is the volume enclosed by the surface. This formula shows the relationship between the surface integral of the vector field and the triple integral of the field's divergence over the enclosed volume.

4. How is the Divergence Theorem related to other mathematical theorems?

The Divergence Theorem is a generalization of several other theorems, including Green's Theorem and the Fundamental Theorem of Calculus. It is also related to the Curl Theorem and Stokes' Theorem, which are both used to calculate line integrals.

5. Are there any limitations to the Divergence Theorem?

Yes, the Divergence Theorem has certain limitations and assumptions. It can only be used for continuously differentiable vector fields, and the surface and volume must be well-behaved. In addition, the theorem is only valid in three dimensions and cannot be generalized to higher dimensions.

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