• Support PF! Buy your school textbooks, materials and every day products Here!

Cant understand this double integral

  • #1
1,395
0

Answers and Replies

  • #2
diazona
Homework Helper
2,175
6
1) Do you understand the meaning of the sum a couple of lines above it?
[tex]k\sum_i \Delta q_i \sum_j \Delta q_j \frac{(\vec{r}_j - \vec{r}_i)}{(\vec{r}_j - \vec{r}_i)^3}[/tex]

2) Do you understand why the sum is equivalent to the integral, when the number of charges is very very large?
[tex]k\int_0^L \lambda \mathrm{d}l_1 \int_{2L}^{3L} \lambda \mathrm{d}l_2 \frac{1}{(l_2 - l_1)^3}[/tex]
 
  • #3
1,395
0
the sum is like Coulomb law but what is the meaning
of sum from i and sum from j
??

i dont know why the this sum equals this integral
??
i know that integral is a sum too
bu thy look different
there is no i and j in the integral
no L in the sum
?
 
  • #4
1,395
0
?????????
 

Related Threads for: Cant understand this double integral

Replies
4
Views
856
  • Last Post
Replies
1
Views
881
  • Last Post
Replies
3
Views
835
Replies
1
Views
714
Replies
1
Views
1K
Replies
2
Views
1K
Replies
3
Views
2K
Replies
22
Views
2K
Top