Recent content by xz5x

@Many_S_Theory Thank you!

Yes.

@Muphrid I know the result, but I have problems with procedure. Can you write down this equation; or just the start? Thanks!

Do free particles have quantum numbers? What are they?

This is what I got for Nabla and Laplace of plane wave. I have problems when I try to write out it with x, y, z coordinates. Can somebody help me? Thanks! http://img213.imageshack.us/img213/9532/85490316.jpg http://img528.imageshack.us/img528/6835/f41cab97f649df5431127b5.png

@zzzoak @hikaru1221Thank you very much!

@hikaru1221 Thank you for your response! Yes, the second step in b) is not correct. This is my new result: [PLAIN]http://img704.imageshack.us/img704/4834/85676997.jpg I can’t get the expected result. Please tell me, is dimension of my new result OK?

@zzzoak I didn't know that average energy may be rewriten in this form. Can you please show me the procedure of how can I get your average energy from mine? I see that you got the right result. I'll try to solve the problem with this form of potential energy. Thank you very much!

Please help me solve this problem: Homework Statement http://img688.imageshack.us/img688/8140/86617607.jpg The attempt at a solution http://img63.imageshack.us/img63/9531/79093945.jpg This is my whole procedure...

Thank you very much!

Is my procedure/result correct? Are these equations relevant for the problem? Many thanks! Homework Statement - blue color on the picture Homework Equations - black color on the picture The Attempt at a Solution - black color on the picture...

But this result is correct. Like Galileo said - I had a good idea but I didn't integrate correctly

Tide, I really don't know what to do with spherical coordinates. Maybe you can show me. But, I found another way..Here it is: nabla x r^4r = = r^4rotr - r x grad r^4 = 0 - r x dr^4/dr r/r = - r x dr^4/dr r/r = - dr^4/dr 1/r rxr = 0 btw. bold are vectors; curl=rot; nablaxnablaf=0...

Oh, yes..now I see my mistake U is Potential. So, the result is: U = -1/2*x^2-2xy-4xz+3/2*y^2+yz-2+C Thank you for your help!

This is what I need: nabla x F F = r^4 r (bold are vectors)..(r is radius vector) The result of this is 0, but I don't know how... Thank you for your help!