- #1
Phymath
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- 0
alright, so i got this potentional equation [tex] \Phi = k_e Q e^{-\alpha r}/r[/tex]
it askes me to find the total charge after calcing the charge density, so
anyway...lets get the field [tex]\vec{E}=-\nabla \Phi[/tex]
so yea then take the divergence fot the charge density
[tex] \nabla \bullet \vec{E} = 4 \pi k_e p [/tex]
so then I am assuming to figure out the "total charge" I am going to use the density in a volume intergral and equate that to [tex] 4 \pi k_e Q_{enclosed} [/tex] but what is my limit? is it is a sphere i can define by radius a as my surface? or what?
next question
finding the potential associated with a Vector field A by line intergration in polar cords (or any cords for that matter) what's that mean
[tex]\oint \vec{A} \bullet d\vec{r} = \Phi (b) - \Phi (a)[/tex] is that what they're talking about let me know
it askes me to find the total charge after calcing the charge density, so
anyway...lets get the field [tex]\vec{E}=-\nabla \Phi[/tex]
so yea then take the divergence fot the charge density
[tex] \nabla \bullet \vec{E} = 4 \pi k_e p [/tex]
so then I am assuming to figure out the "total charge" I am going to use the density in a volume intergral and equate that to [tex] 4 \pi k_e Q_{enclosed} [/tex] but what is my limit? is it is a sphere i can define by radius a as my surface? or what?
next question
finding the potential associated with a Vector field A by line intergration in polar cords (or any cords for that matter) what's that mean
[tex]\oint \vec{A} \bullet d\vec{r} = \Phi (b) - \Phi (a)[/tex] is that what they're talking about let me know