How Does Gauss' Theorem Transform Volume to Surface Integrals?

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Gauss' theorem, also known as the divergence theorem, relates volume integrals of the divergence of a vector field to surface integrals over the boundary of the volume. The transformation from the volume integral of the Laplace operator applied to a function J to the surface integral involves applying the divergence theorem. It is clarified that Gauss' Law cannot be used to prove this relationship, as the divergence theorem is a more general principle. The discussion confirms that understanding this process is essential for solving related problems. Overall, the divergence theorem is a fundamental tool in vector calculus for connecting volume and surface integrals.
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how -∫(v)laplace functor *J*dτ change into -∮(s) J(n) dS using Gauss formula?
 
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Do you mean

\int_V \vec \nabla \cdot \vec J d\tau = \oint_S \vec J \cdot d\vec S
under the appropriate conditions on J, S and V.

This is the divergence theorem (also called Gauss' or Ostrogradsky's theorem). You cannot use Gauss' Law (if that is what you meant) to prove this. the divergence theorem is stronger and can be used to prove Gauss' law.
 
ok thanks! it's just our teacher told us to prove this equation by Gauss' theorem.and now I've known the process.thanks!
 
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