Recent content by castlemaster

Hi, I think I see question 2 now. The Bessel functions are only finite at the origin when the order \nu is a positive integer. Then I only have to be sure K is big enough for the Bessel functions to have 3 zeros, that's it bigger than 5.1356 which is the first zero of J2 . This gives me a...

Homework Statement Find the eigenfunctions (with angular momentum 0) and the estimation of the 3 first energy levels (given g and a) of a particle in a exponential potential such as V = -ge-r/a Homework Equations Time independent Schrödinger equation (SE)The Attempt at a Solution Did a...

Maybe it easier to see with the equations for B' and E' parallel and perpendicular to the velocity (I've read those are equivalent to the above for E' and B' http://en.wikipedia.org/wiki/Classical_electromagnetism_and_special_relativity) Thanks

E can't be parallel to v or B' won't vanish, right?

Hi, Should I use the fact that E.B=E'.B'=0 and merge the equations from E' and B'? Cause I don't see a simple way of taking the velocity out of there. Thanks

Homework Statement We have an homogeneus electromagnetic field with E \bullet B=0 and E \neq cB Find the velocity of the reference frames in which ony E exists. Homework Equations \mathbf{E}' = \gamma \left( \mathbf{E} + \mathbf{v} \times \mathbf{B} \right ) - \left...

You are right qbert, I was just doing a stupid mistake everytime. ln(a*b) = lna+lnb RIGHT ln(a+b) = lna+lnb STUPID ln(1+ax) aprox.= ax for a small thanks for the patience

if I do u=\frac{\beta mw^2x^2}{2} then I get something like \frac{1}{\beta mw^2}\int{e^{-u}e^{-\frac{4\alpha u^2}{\beta m^2w^4}}} I think it approches what I need to end with, at least the variables are similar, someone has a clue? maybe using the fact that the derivate of exp(ax^n) is...

That's what I thought but part b of the problem say: show that C_{v}=Nk(1-\frac{6*\alfa*k}{m^2w^4}T) but E=-\frac{d lnZ}{d\beta} and C_{v}=\frac{d E}{dT} if I do all the integrals I get something like ln Z=Nln(K_{1}\beta^{n}) and for the properties of the ln ln Z=Nln(K_{1})...

Homework Statement Having a unidemsional array of N oscillators with same frequency w and with an anharmonic factor ax^4 where 0 < a << 1 Calculate, up to the first order of a, the partition function. Homework Equations For one oscillator...

\Delta P=\left(\langle P^2\rangle-\langle P\rangle^2 \right)^{1/2}\neq\langle P^2\rangle yes I have it in mind thank's a lot

I think is this: \langle P\rangle=|c1|^2(2\hbar/L) + |c2|^2(4\hbar/L) \langle P^2\rangle=|c1|^2(2\hbar/L)^2 + |c2|^2(4\hbar/L)^2 You are right in the coefficients, I recalculated them.

I didn't have the paper with me the first time I wrote the wave function, I thought the k's were there. Anyway what I want is to know how to proceed as I'm sure that the exact same problem won't be in the september test. And uncertainty? \langle P^2\rangle=|c1|^2(2\hbar/L)^2 +...

This is from a spanish university examination. This is a pretty fair translation: A particle of mass m travels freely in one dimension. In t=0, the wave function (non-normalisable) of the particle is \Psi(x,0)=Acos^2(x/L)e^{2ix/L} a) Find, for...

No, it starts by giving \Psi(x,0)=Acos^2(kx/L)e^{2ikx/L}