Register to reply

Quantum Mechanics Expectation

by roshan2004
Tags: expectation, mechanics, quantum
Share this thread:
roshan2004
#1
Jun16-10, 01:32 PM
P: 139
1. The problem statement, all variables and given/known data
1. Calculate the expectation value [tex]<p_{x}>[/tex] of the momentum of a particle trapped in a one-dimensional box.
2. Find the expectation value <x> of the position of a particle trapped in a box L wide.


2. Relevant equations
[tex]\psi _{n}=\sqrt{\frac{2}{L}}sin \frac{n\pi x}{L}[/tex]
[tex]<p_{x}>=\int \psi^*p_{x}\psi dx[/tex]
[tex]<x>=\int \psi^*x\psi dx[/tex]


3. The attempt at a solution
I got confused on choosing the limits for both the problems for integrating them. What's the limits I should chose for both the problems.
Phys.Org News Partner Science news on Phys.org
Wildfires and other burns play bigger role in climate change, professor finds
SR Labs research to expose BadUSB next week in Vegas
New study advances 'DNA revolution,' tells butterflies' evolutionary history
Doc Al
#2
Jun16-10, 02:03 PM
Mentor
Doc Al's Avatar
P: 41,326
Where is Ψ non-zero? (What are the boundaries of the box?)
roshan2004
#3
Jun16-10, 02:14 PM
P: 139
x=0 and x=L

roshan2004
#4
Jun16-10, 02:17 PM
P: 139
Quantum Mechanics Expectation

Thanks I got it. The limits that I have to use are x=0 and x=L
Doc Al
#5
Jun16-10, 02:22 PM
Mentor
Doc Al's Avatar
P: 41,326
Exactly.


Register to reply

Related Discussions
Suggestion: Sub-Forum for Interpretations of Quantum Mechanics Forum Feedback & Announcements 10
Any comments on Mathematical Foundations of Quantum Mechanics by Parthasarathy Math & Science Software 0
What are the classical Textbooks for quantum mechanics and electromagnetism? Science & Math Textbooks 8
Any comments on Mathematical Foundations of Quantum Mechanics by Parthasarathy Math & Science Software 0
Introduction to Quantum Mechanics - Third Edition, by Richard Liboff General Physics 12