# Particle in a box

1. Apr 1, 2007

### cscott

1. The problem statement, all variables and given/known data

In a region of space, a particle with zero total energy has a wave function
$$\Psi (x) = Axe^{-x^2/L^2}$$

Find the potential energy U as a function of x.

3. The attempt at a solution

I don't understand how this particle can have zero total energy? Wouldn't this imply that the potential energy is simple 0 everywhere...

2. Apr 1, 2007

### cscott

Wait, would I have to describe the potential like we do for an infinite square well?

3. Apr 1, 2007

### christianjb

Use time-independent Schrodinger eqn.

Zero total energy means that PE=-KE.

4. Apr 1, 2007

### cscott

So with E = 0 I can say $$\frac{d^2\Psi}{dx^2} = -\frac{2mU}{\hbar ^2} \Psi$$

which mean I can get solutions just like in my text but I don't what I can apply as boundry conditions or how to get U in terms in x.

Last edited: Apr 1, 2007
5. Apr 1, 2007

### christianjb

Divide both sides by psi(x) to get U(x).

psi(x) already obeys the relevant boundary conditions.

6. Apr 1, 2007

### cscott

Ah I see now :P I feel kind of stupid :\

Thanks!

7. Feb 23, 2008

### giffary

thanks!!!

8. Feb 23, 2008

### andromeda2008

i would lke to b informed how to prepare a lab report on the Hall Effect hopping that i will b given an intensive help over the matter
N.B...i did the experment of the hall effect when a moving conducter moves through a magnetic fild while two variable resistors of 8 and 16 ohms connected to it and the source and the ammeters so as to had the observation
hopping that i will b directed sufficently
urs faithfully......................