Particle in a Box: Homework Statement & Equations

In summary, the conversation discusses a problem involving L^2 and its relation to energy in a 2D particle in a box. The formula for 1D particle in a box is used, but it is pointed out that for a 2D box there should be 2 quantum numbers. The wavefunctions and energies for the 2D box are given, but there is still difficulty in determining the quantum numbers. It is suggested that the ground state is n=m=1 and the next highest energy level would be the first excited state. There is also mention of degenerate level considerations and confusion about why the original problem statement was deleted.
  • #1
chemasdf
3
0

Homework Statement



hi

Homework Equations





The Attempt at a Solution

 
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  • #2
Hey Chemasdf,

Welcome to PF!

In respect to your question, L^2: an area maybe? I hope someone will correct me if I'm wrong that this can be manipulated.

The Bob
 
  • #3
chemasdf said:

The Attempt at a Solution


I have tried relating it to Energy in the equation E=(n^2*h^2)/(8mL^2). It is a 2D problem for particle in a box

You're using the formula for the 1D particle in a box. If you're talking about a 2D box then there should be 2 quantum numbers, not just one.

Wavefunctions and energies for the 2D box are given below.

[tex]\psi_{m,n}(x,y)=\frac{2}{\sqrt{L_xL_y}}\sin\left(\frac{m\pi x}{L_x}\right)\sin\left(\frac{n\pi y}{L_y}\right)[/tex]

[tex]E_{m,n}=\frac{\hbar^2\pi^2}{2m}\left[\left(\frac{m}{L_x}\right)^2+\left(\frac{n}{L_y}\right)^2\right][/tex]
 
  • #4
I'm still having trouble determining the quantum numbers (n). Can someone give me a hint as to how to solve for "n". I cannot find the wavenumber without knowing the "n" which is not given. Thanks
 
  • #5
The ground state is [itex]n=m=1[/itex]. I would take the first excited state to be the next highest energy level.
 
  • #6
does this calculation involve any degenerate level considerations?
 
  • #7
Why on Earth did you delete the problem statement?
 
  • #8
maybe he found the answer? but then he should have deleted the post, not the question...o_O weird...
 
  • #9
Even if he did find the answer, people took the time to reply. It's disrespectful to destroy a thread like this.
 

1. What is a "Particle in a Box"?

A "Particle in a Box" is a simplified model used in quantum mechanics to understand the behavior of particles confined to a small space. The box represents the boundaries within which the particle can move, and the particle is assumed to have no potential energy outside of the box.

2. What is the homework statement for "Particle in a Box"?

The homework statement for "Particle in a Box" typically involves calculating the energy levels and wave functions for a particle confined to a one-dimensional box of a given size. It may also involve solving for the probability of finding the particle at a specific location within the box.

3. What are the equations used for "Particle in a Box"?

The equations used for "Particle in a Box" include the Schrödinger equation, which describes the time evolution of the particle's wave function, and the boundary conditions that must be satisfied at the edges of the box. The energy levels can be found using the equation E = n²h²/8mL², where n is the quantum number, h is Planck's constant, m is the mass of the particle, and L is the length of the box.

4. What are the assumptions made for "Particle in a Box"?

The assumptions made for "Particle in a Box" include the particle being confined to a one-dimensional box with infinitely high potential walls, and the particle not interacting with any external forces. These assumptions allow for a simplified model that can be used to understand the behavior of particles in more complex systems.

5. What real-world applications does "Particle in a Box" have?

The concept of "Particle in a Box" has applications in various fields, such as solid state physics, chemistry, and materials science. It can be used to understand the behavior of electrons in a crystal lattice, the properties of atoms and molecules in a confined space, and the behavior of particles in a potential well. It is also used in the development of quantum computing and nanotechnology.

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