Recent content by lmcelroy

This isn't a homework problem. I am preparing for a particle physics exam and although I understand the theoretical side of field theory, I have little idea how to approach practical scattering questions like these. THE PROBLEM: Dark matter might be observed at the LHC with monojet and...

Yes, the exact same method can be applied. A typical "text-book example" gives an infinitely long wire with a linear charge density λ. Just as with a cylinder a cylindrical Gaussian surface can be used for a wire (a wire in reality is really just a thin cylinder so this makes sense). For your...

^Thanks for that. An easy to follow derivation and explanation even for someone new to the calculus of variations, as myself.

Anyone willing to derive the motion equations of special relativity from the SR action: S = -m0c2∫t1t21/γ dt where: m0 = rest mass γ = Lorentz factor =1/√(1-v2/c2) v is the velocity as a function of time. The full action contains terms of the vector potential and scalar potential but assume...

There are many factors that influence the Earth's rotation, none of which is its mass. Check this out: http://en.wikipedia.org/wiki/Earth's_rotation#Origin

Ok, after obtaining a copy of Feynman's lectures and referring to Volume 2, Chapter 33-3, I think I have found a solution. Treating the boundary as a separate region (media 3 with a relative permittivity that begins at εr1 and changes continuously to εr2) then since the P field is different...

This was obviously posted a while ago, answering may help others though so: Begin by constructing a cylindrical Gaussian surface of radius r and length l around the cylinder. Then the electric field outside of the cylinder is, by Gauss's law: \ointE.da = Q / ε0 where Q is the total...

Not actually a homework question, this is a question from a past exam paper (second year EM and optics): Homework Statement Use a Gaussian surface and Amperian loop to derive the electrostatic boundary conditions for a polarization field P at an interface between media 1 and 2 with...