Recent content by Waxterzz

Excuse me sir, for the late reply. I think I didn't understood it first, then forgot about it, now I stumbled across it and still haven't figured it out ρ . A . d = σ . A ρ . dx = σ Is this what you were implying?I don't see how R sin θ dθ equals the thickness of my disk, since R sin θ points...

Hi all, According to wikipedia: Can someone explain to me with a mathematical proof the following: $$ \frac {\partial f(x)} {\partial v} = \hat v \cdot \nabla f(x) $$ I don't get this identity except the special example where the partial derivative of f(x) wrt x is a special kind of a...

I think the solution is just wrong because the last step isn't correct? Edit: Looks like the solutions manual from Zangwhil contains errors. This is from a site I found on the internet (check problem 4d) https://pa.as.uky.edu/sites/default/files/Phy416G-HWSol4.pdfbut now dσ = 2πρR sin θdθ...

Find E(r) inside and outside a uniformly charged spherical volume by superposing the electric fields produced by a collection of uniformly charged disks. a+b) Given equations, sketch of problem This is the equation in the handbook for a disk (but in the exercises the z becomes x, without loss of...

Hi, Here is the complete exercise and solution from Zangwhil Modern Electrodynamics. Since my question is about the levi-civita symbol, I thought it would be better to post it here since it is a tensor. So in the step e(ijk) D(jk) = e(ijk)D(jk) + e(kj)D(kj) So The e(kj)D(kj) part is wrong and...

Hi all, Can someone explain me the last two steps? I don't know why suddenly there is a term with only two indices, and then in the last step you do something distributive and again three indices. Thanks in advance

Ok, so partial integration. integral (fdg) = fg - integral (gdf) f = z-Ru dg = du / (R² +z² -2zRu) ^ 3/2 For g I get 1 / ( (Rz) * (R² + z² -2*R*z*u)^1/2) fg = (z-Ru) / ( (Rz) * (R² + z² -2*R*z*u)^1/2) now the integral part - integral ( g d f) df = -R du So The integral to solve Rdu /...

I get something extremely messy. Here is the first part, the second part with integration by parts,I'll do it again tomorrow. So the first term integral (z du / (R² + z² - 2 Rz u) ^3/2 ) d(R² + z² - 2 Rz u) = -2 R z du The integral becomes -1/2R * integral ( d(R² + z² - 2 Rz u) / (R² + z²...

Hi all, "Integral can be done by partial fractions - or look it up" So second line, that's what I want to do. How to deal with this? What substitution can I use? Never encountered partial fractions with non-integer exponents. Someone give me a tip? Thanks in advance

Hi myself, I found out I need to include something like 1- ( stuff going in the z direction after k scattering) / (stuff that would go in z direction if there was no scattering at all), so 1 - k' projected on z axis /k = 1 - (k cos theta) / k Yes, I'm a noob. So I'll start over. :')

Hi, Sorry for the late reply. Hope this is somewhat more clear, because last post was a bit messy. Still haven't learned LaTex. Is this valid? I couldn't evaluatie the last integral, because of the square. Do I need to use partial fractions? Thanks

This is what I got uptil now, but I have to leave. Thanks for help, give me feedback if you want to, and I will post update when I'm back, probably tomorrow. Thanks for the patience anyway!

It's been this the whole time?, with r being k' Ps: After this I'm going to finally learn LaTeX

How come dk' is a volume element, it's the derivative of a vector. Most textbooks, the volume element is called a d tau or a dV My head is a mess. It's like I completely forgot how to calculus. Good news: I know I'm wrong. Really don't see it

Mr 6 hours and I still have no clue, can you please hold my hand and solve it with me. I mean, just say what I have to do, I will solve it, but give me instructions. I mean what's the deal with the dirac function and the dk', it's supposed to be a volume element and the dirac term, why isn't...