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Spoony
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For divergance thereom, say i have a volume integral to calculate of form [tex] \iiint_V \nabla F dV [/tex]
i can relate it to the form:
[tex] \iint_S F.dS = \iiint_V \nabla F dV [/tex]
and calculate using the left hand side,
[tex] \iint_S F.n dS [/tex]
where n is the unit vector normal to the surface of integration.
for my surface I have a cylinder.
of form x^2 + y^2 =< 1 for 0 =< z =< 3
So splitting this up brings me 3 surfaces, the top 'cap' the bottom 'cap' and the part around the middle. i can compute by intergrating the vector field seperately over each surface (i think) and summing over each suurface.
question is do i use the same normal vector for all surfaces ie the normal to the main surfaces, or do i for each separate surface use a different normal vector?
i switched to cylnderical co-ords to solve this.
i assumed at first it was a separate normal for each vector. but this gave me a dot product of zero for the area of the strip aroundthe cylinder.
i can relate it to the form:
[tex] \iint_S F.dS = \iiint_V \nabla F dV [/tex]
and calculate using the left hand side,
[tex] \iint_S F.n dS [/tex]
where n is the unit vector normal to the surface of integration.
for my surface I have a cylinder.
of form x^2 + y^2 =< 1 for 0 =< z =< 3
So splitting this up brings me 3 surfaces, the top 'cap' the bottom 'cap' and the part around the middle. i can compute by intergrating the vector field seperately over each surface (i think) and summing over each suurface.
question is do i use the same normal vector for all surfaces ie the normal to the main surfaces, or do i for each separate surface use a different normal vector?
i switched to cylnderical co-ords to solve this.
i assumed at first it was a separate normal for each vector. but this gave me a dot product of zero for the area of the strip aroundthe cylinder.
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