Trouble with Harmonic Oscillator Problems in Quantum Physics

AI Thread Summary
The discussion centers on difficulties with harmonic oscillator problems in quantum physics, specifically regarding the wave function for n=1. The user is confused about the complex conjugate of the wave function and its implications for calculating the expectation value <x>, questioning why certain exponential terms seem to cancel out during integration. Additionally, there is uncertainty about deriving <p> when <x> appears to be time-independent. A response suggests a potential oversight in the variable used for "r," which could clarify the integration issue. The conversation emphasizes the importance of proper variable definition and adherence to forum posting guidelines.
Tuneman
Messages
41
Reaction score
0
I am having trouble with 2 problems about the harmonic oscilator.
I realize this isn't the homework section, however I feel that in my situation where time is limited, perhaps someone would be able to give me a certain amount of leeway.


First of all the question tells me to use the wave function for when n=1

So I have:
Wavefunction = A[1]*r^1/2 * e^-((r^2)/2)


where r= (mw/(hbar))^1/2 and A[1] is A sub 1.

I am wondering when I am multiplying this by the complex conjugate, is the complex conjugate going to have a e^+((r^2)/2). I don't think I am but for some reason, in a solution finding <x> which equals ](integral) psi* (times) x (times) psi] those exponential functions did not appear. So I was wondering how they canceled out when you calculate <x>

also it asks me to calculate <p>, which I know equals m*d<x>/dt. My question is, if my <x> does not depend on t, because the time dependent part of the equation was canceled out when solving for <x>, how can I find d<x>/dt?

Any help would be appreciated, I'm sure my questions or equations aren't too clear, so if you have any questions, I will try to clarify. Thank you.
 
Physics news on Phys.org
Tuneman said:
I am having trouble with 2 problems about the harmonic oscilator.
I realize this isn't the homework section, however I feel that in my situation where time is limited, perhaps someone would be able to give me a certain amount of leeway.


First of all the question tells me to use the wave function for when n=1

So I have:
Wavefunction = A[1]*r^1/2 * e^-((r^2)/2)


where r= (mw/(hbar))^1/2 and A[1] is A sub 1.

This doesn't make sense: I'm sure you are missing a space variable in "r".
That explains then too why you don't find your exponential anymore once you've integrated over it...

cheers,
Patrick.

PS: and this really belongs in the homework section...
 
Tuneman, please don't double post. One thread is enough for one question.
 
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Back
Top