Talk:Conservative force

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needs refs, try finding some here.--Cronholm144 23:00, 28 May 2007 (UTC)

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Help with this template Comments: edit – history – watch – refresh needs refs, try finding some here.--Cronholm144 23:00, 28 May 2007 (UTC)

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Isn't it the force field, rather than the force itself, that is conservative? Michael Hardy 20:55, 29 May 2004 (UTC)

Certain forces (in the sense of phenomena, not vectors; e.g. gravity) always generate conservative force fields, and others (like the obvious friction) never do (and in fact could be argued not to generate force fields at all). --Tardis 04:52, 31 October 2006 (UTC)

I removed magnetism as a nonconservative force; the cyclotron frequency (neglecting cyclotron radiation) seems to counterindicate it. Just because $\nabla \times \mathbf{B} \not= 0$ doesn't mean that the force is nonconservative! (Of course, time-changing magnetic fields can impart momentum, but that's separate.) Just drawing attention to this edit in case I'm crazy. --Tardis 04:52, 31 October 2006 (UTC)

[edit] My edit

I tried to make the page a bit more accessible to the general public, to start with. I'll try to create an image, but I'm not good at that so I'll hope someone improve on me :) Considering the above discussion, I inserted the magnetic force again, but added a remark about time-independency of the electric field (Maxwell says: rot B = - dE/dt). Hope this will give people a nudge to start editing. --CompuChip 16:39, 5 December 2006 (UTC)

And I apologize for the apostrophe abuse... Should have known better --CompuChip 18:22, 15 December 2006 (UTC)

[edit] Edit

CompuChip, you are mistaken here : the magnetic force conserves energy even in time-dependent electric fields, not because of Maxwell but because of the Lorentz Force, which is what matters here (we are talking of forces, not fields). F = q V^B, thus P = F.V = q(V^B).V = 0, and the energy is conserved in every path. Besides, the Maxwell equation you cite is false, it's rotE = -dB/dt : the electric force is conservative in time-independant magnetic fields. I'm editing this, as well as other examples ("it is known from experiment" : the experiment has no place in this, it follows from the law of gravity). I'm also removing the proof of path independence, which is elementary and can be simply described instead of a "heavy" mathematical formulation. It would be nice to speak of potential energy in this article, i dunno how to do it without being too specific. Also, english is not my primary language, so feel free to correct me if i have done any mistake. Smeuuh 21:44, 5 August 2007 (UTC)

Any given force doesn't necessarily conserve energy in itself in time dependent fields- however conservation of energy still applies- the whole system has to conserve energy.WolfKeeper 20:09, 19 September 2007 (UTC)