Recent content by chaotic

thank you for your help. i will try now.

thank you but we did not do perturbation theory. actually this is takehome and it can be further subject which we did not know. if it is about perturbation theory how can i start and how can i solve it? what is the way of it? i have 3-4 hour :)

Homework Statement Homework Equations a(+) = (-ip+mwx)/(2hmw)^1/2 a() = (+ip+mwx)/(2hmw)^1/2 The Attempt at a Solution can i use these operators to solve this problem? please help me i need to give this homework tomorrow morning :confused:

Homework Statement there is a infinite quantum well with size L and there is a particle in it with mass m. suddenly the size of the quantum well is doubled. What will be the wave function at a later time t ? Homework Equations ψ= \sqrt{2/L} sin (n pi x / L) E = n^2 pi^2 h^2 / 2mL^2...

Homework Statement how can we find the force particle exert on the walls for classical particle which is the infinite quantum well of length L and particle mass is m? Homework Equations E=h^2 pi^2 n^2 / (2ml^2) for quantum The Attempt at a Solution and F = -dE / dL = h^2 pi^2 n^2...

me too. I am very confused. can you just tell me how can i find <x(t)> and <x(t)^2>

thank you for your answer. now i am trying that \frac{dψ}{dt} = \frac{iħ}{2m} d2ψ/dx2 after that i find that; (i send dt to right side) ψ = ∫ \frac{iħ}{2m} d2ψ/dx2 dt but i don't know how can i take the integral of right side? after that i will use the <x> = ∫ψ* x ψ is that...

i even don't know what is the time evoluation of varience? what is that?

Homework Statement http://img853.imageshack.us/img853/2532/70224197.png Homework Equations i know schrödingher eq. and basic quantum formula The Attempt at a Solution i showed that the equality at the first question but i can not start from (a) part. how and where am i supposed to start...

thank you very much. i think i can solve it after your help.

aghh i get all A,B,C = 0 :confused::confused: i attached the solution; http://imgur.com/rtBpCl.jg where am i doing wrong?

Homework Statement Homework Equations -h^2/2m d^2F(x)/dx^2 = EF(x) The Attempt at a Solution i just need to a part. for E<0 i can find for 0<x<L side F(x) = ACos(Lx) + BSin(Lx) at the L<x side, F(x) = e^(Kx) where L^2= 2m(E+V)/h^2 K^2= -2mE/h^2 but i do not know what will i do. can...

yes it is very confusing I am trying to find solution for 2 hours just because of that it is funny it takes my precious time :)

agh :) thank you very much i understand now :)

when i take the same derivative with wolfram i get another result http://www.wolframalpha.com/input/?i=d%28e%5E%28-kx%29+e%5E%28icx%29%29%2Fdx