Article View: sci.physics
Article #1253A quantum mechanics question
From: Message from the Starship Enterp...
Date: Thu, 16 Apr 1992 23:27
Date: Thu, 16 Apr 1992 23:27
47 lines
2172 bytes
2172 bytes
+ +
+ +
V(x)=OO + V(x)=0 + V(x)=OO (infinite potential to the right
+ + and left on the well)
++++++++++
x=0 x=a
Suppose you have a particle (1-D) in an infinite square well ....
assume also that the state of the system is the ground state of the
box, so |Psi> = sqrt (1/a) sin kx. If BOTH walls disolve at t=0,
the probability distributions of energy and momentum can be calculated
from Q(E)=|<En|Psi>|^2 and taking advantage from the fact that the
Hamiltonian and Momentum operators conmute for this particular new
state. All is joy and happines :-)
Now, consider the particle in the box problem again. Now at time t=0
only the left side of the wall vanishes. The energy distribution can
be calculated using the formula above. How do you calculate the momentum
distribution????? - [H,P] =! 0 anymore .... -this is an old homework
problem I never solved ... thanks in advance
+
+
V(x)=OO + V(x)=0
+
++++++++++++++++++++++++++++++++++++
x=0
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$^$ "I perceive the Universe as ^^^^^^ Jose Luis Paredes $^$
$^$ a single equation .... and ^^^^^^ Physicist by choice !! $^$
$^$ it's so simple!" ^^^^^^ University of Houston $^$
$^$ Lt. Barkley -Star Trek TNG ^^^^^^ Jose@crcc.uh.edu $^$
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Newsgroups: sci.physics Path: arc1-ca.pugleaf.net!sparky!uunet!zaphod.mps.ohio-state.edu!menudo.uh.edu!Rosie.UH.EDU!CRCC6 From: crcc6@Rosie.UH.EDU (Message from the Starship Enterprise) Subject: A quantum mechanics question Message-ID: <1992Apr16.232748.5770@menudo.uh.edu> Sender: usenet@menudo.uh.edu (USENET News System) Nntp-Posting-Host: rosie.uh.edu Reply-To: crcc6@Rosie.UH.EDU Organization: University of Houston Date: Thu, 16 Apr 1992 23:27:48 GMT Lines: 47