Recent content by fyzxfreak

Well, I don't know - I'm kinda confused about the pulley. I was thinking that the pulley can't really "pull" M_2, because it just slides past the string, redirecting the force. What I was thinking is that if just the right force F is applied, M_3 doesn't accelerate, and due to the...

Actually, now that I think about it, I guess it makes sense. If M_3 is not moving (in respect to M_1), M_2 is moving to the right, and therefore the force is acting on it as well (through tension).

Homework Statement A pedagogical machine is illustrated in the sketch, yatta yatta, what force F must be applied to M_1 to keep M_3 from rising or falling? No friction. Here's the http://www.slideshare.net/brigittperalta/sol-maquina-pedagogica-1546585" . The Attempt at a Solution If we...

I've also recently come across the need for black-box optimization. I have some function f[a0, a1, ... an] that I've defined using the delayed notation ":=" (because it consists of numerical integrals that take a couple of seconds each to compute) and I want to minimize it in respect to a0, a1...

Good! Glad to be of help! Hopefully it's correct! :smile:

Ah, well I think what I mean by nothing happens is that from the point of view of the outer capacitor-shell, there's the inner +Q but also the -Q that formed from grounding the inner capacitor-shell. Thus, there is no net enclosed charge inside the outer capacitor-shell and therefore no field...

Haha, really? Whoops, I felt like I had no idea what I was talking about. So what grounding does is hook the inner shell up to a zero potential of sorts... which is why the positive charges would like to leave? ... while the negative charges stay attracted to the +Q? For the outer shell...

Hunh, that's interesting. Could someone please explain how grounding works in the presence of these other charges? =EDIT= Wait a second... grounding means some set low potential, right? So in that case there is zero potential difference between the inner and outer capacitor-parts? So there's no...

Is there a systematic method of approaching this problem? i.e. application of Maxwell's equations, etc. =EDIT= There'd definitely be some variational calculus involved (for the different paths from point A to point B). Yeah... this problem does not seem particularly simple anymore, haha.

Hello fellow physics-people, I was just thinking about the following setup: We have a conducting surface (with smoothly varying resistivity) hooked up to some battery with the wires contacting the surface at two arbitrary points, A and B. How would we go about figuring out the current...