Recent content by folgorant

thank you very much Redbelly98...now it's okay! i've used: N=N(0)exp(-t/T) and then dividing for 3 the result is correct! thanks...

yes... if N is total number of atoms; y=1/8000 is the decay rate (number of decay/sec) t= 1 hours = 3600sec is the period atoms be in the box so: 1/8000 * 3600 * N = 0.45N i.e. the percentage of atoms remaining in excited state is 55%. after this..i should evaluate the probably...

the answer is: 21.25%

Hello! i have a trouble with an exercise of a course of structure of matter. Helium atoms in the excited state 23S1 come out from a box at v=2000 m/s and pass trough an Stern & Gerlach apparatus with dB/dz=25 T/m and length L=0.30m. Atoms spends 1 hour in the box and the average-time for...

precision okay, it's 1 Coulomb = 3 x 10^9 esu (or Cstat) but the problem is not solved!

Hi all! Homework Statement The problem is: For a particle with electric charge equal to that of one electron, the trajectory radius R is related to the absolute value of the perpendicular component P_{\bot}of the relativistic moment perpendicular to \textbf{B} from the relation...

hi all, I have a problem about rotation operator in QM. I must verify that (\hat{U}(R)f)(\textbf{x})=f(R^{-1}\textbf{x}) with: \hat{U}(R) = exp({\frac{-i\varphi\textbf{nL}}{\hbar}}) R rotation on versor n of angle \varphi I don't really know how to start, so please give me an advice!

...continue: and the next is what I found with another method: (\frac{- \hbar ^2}{2 \mu} \frac{\partial^2}{r \partial r^2} r + \frac{\hbar^2 l(l+1)}{2 \mu r^2 } - \frac{m \omega^2 r^2}{2}) R(r) = E R(r) \rho=\alpha r \alpha=\sqrt{m \omega/ \hbar} dr=\frac{d...

(\frac{- \hbar ^2}{2 \mu} \frac{\partial^2}{r \partial r^2} r + \frac{\hbar^2 l(l+1)}{2 \mu r^2 } - \frac{m \omega^2 r^2}{2}) R(r) = E R(r) u(r)=rR(r) \frac{\partial^2}{r \partial r^2} r = \frac{\partial}{r^2 \partial r}(r^2 \frac{\partial}{\partial r}) u_{kl}(r) =...

but...is my post n°5 correct?

malawi: ops...I see now the "source" of solution you give to me

if I make the substitution : u(r)=rR(r) it become: (\frac{- \hbar ^2}{2 \mu} \frac{\partial^2}{\partial r^2} + \frac{\hbar^2 l(l+1)}{2 \mu r^2 } - \frac{k r^2}{2}) u(r) = u R(r) ...isn't it?? so... after find the solution to be u_{kl}(r) = r^{l+1}e^{-\nu r^2}L^{l+1/2}_k(2\ny...

Hi to everybody of PF community! I have some troubles to find eigenfunctions common to H, L_{z}, L^2 in the problem of spherical simmetric harmonic oscillator. I start with the Hamiltonian H=\frac{\textbf{p}^2}{2 \mu} - \frac{1}{2}k\textbf{x}^2 that in spherical coordinates become...

ah,ok...yes,i have the solution for <k>...but not for phi(p)...neither in any book!

no but...yes..I can try to evaluate <K> using phi(p) instead the phi(r) and should obtain the same result ,no? can I ask you where are you from malawi?