Recent content by lordkelvin

Hi, physics undergraduate here. I don't know much about differential geometry yet, but I'm curious about this idea: Say I encounter a boundary value problem, and I'm not sure what coordinate system would be 'easiest' to solve the problem in. Is there some way to put the differential...

I have a dispersion relation that involves some constants (and it's in natural units so no c or hbar shows up). I'd like to plot E versus k using this equation with k and E in SI units. There are some terms with k^2/(2m) so I can just multiply those by hbar^2, but then there's another term that...

How can I convert an equation in units where hbar = c = 1 into an equation with hbar and c in SI units? I searched around a bit and wasn't able to find anything (I'm probably not asking the right question). Is there some general way to do it rather than just intuition from having seen the...

has any work been done trying to understand the properties of long chains of oscillatory functions? like f(x) = sin(sin(sin(sin(cos(sin(cos(x))))))) for example, or something like e^e^e^e^e^e^e^e^e^e^z)

I get zero. I think this is so since Ylm(θ,\phi) = const* e^(i*\phi)*Plm(cos(\theta) and so the integral over phi yields zero.

Homework Statement Evaluate the integral ∫∫dΩ V(Ω)Yml(Ω) for V(Ω) = +V0 for 0<θ<π/2 ; -V0 for π/2<θ<π Homework Equations I was hoping to apply the orthonormality properties of the spherical harmonics but this is a little more difficult since the integral breaks into two integrals over...

Homework Statement Calculate the electron concentrations (# electrons/atom) needed for the fermi sphere to contact the zone faces (first bril. zone edges) in BCC and FCC structures. Homework Equations kf = (3*pi^2*n)^(1/3) where n is # electrons per atom. For cubic structures...

I'm currently in classical mechanics, and we're doing collisions and two body problems currently. A good portion of the material is covered only in the notes. I could use some supplementary materials. I've looked around on the internet but I haven't found any good resources yet. I was...

I can't get my latex fixed. Anyway, 'mu' should be a mu in the x dot equation, and the T equation shouldn't appear up top, instead it should say the force due to weight is minus mg in the y hat dir. and v should end after the \\

Homework Statement A block of mass m slides down a plane inclined at an angle theta with initial velocity v down the slope and with friction coefficient mu. Find T, the time in which the block comes to a rest due to friction. Use coordinates with y vertical and x horizontal. Homework Equations...

Woah me too! I didn't even realize I bumped something so old lol

You should talk to some professors you've had who work in your area(s) of interest and ask for some guidance. They might be happy to help you out.

Mathematical Methods Electromagnetism II Classical Mechanics II (Thinking about replacing this with a complex analysis course) Modern Physics Special Topics: GRE Prep

I think it's really hard at first to be motivated to study mathematics. Math is cool, and math is useful, but there is A LOT to know before you really know math, and the breadth of the subject can definitely be a source of discouragement. If you like math, then the structure of university...

Yes the original vector function is of constant magnitude. Take a vector function r(t) of constant magnitude and then r dot should be orthogonal to r. I don't understand why.