Calculating Energies in Box Potential

In summary, the box potential V(x) is given by 0 for 0 < x < a and 1 elsewhere. The energies of the ground state, first excited state, and second excited state are estimated for an electron enclosed in a box of size a = 10E-10 m and for a 1 g metallic sphere moving in a box of size a = 10 cm. The energy values are expressed in electron volts and joules, respectively. The equations used for the calculations are E1 = ((h)^2) / (8 * m * L^2) and En = n^2 * E1. The significance of quantum effects for both systems is discussed, with the issue of defining the length L for
  • #1
Messy
5
0

Homework Statement



Consider the box potential
V (x) = 0 0 < x < a
1 elsewhere

a) Estimate the energies of the ground state as well as those of the First and second
excited states for
i) an electron enclosed in a box of size a = 10E-10 m. Express your answer in
electron volts.
ii) a 1 g metallic sphere which is moving in box of size a = 10 cm. Express your
answer in joules.
b) Discuss the importance of quantum effects for both these two systems.

Homework Equations



E1 = ((h)^2 ) / ( 8 * m * L ^2)

En = n^2 * E1

The Attempt at a Solution



The First problem is , I am not sure about L(Length) . Is this equal to the size of the box 'a' in part i and ii.

The Second Problem is how can i define the importantance of quantum effect (b) .. I mean should i have to define with the varying size what change i am observing in Energy Levels .
 
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  • #2
May be i have to put this one in Advance Physics Sections :-)
 
  • #3


I would like to address the homework statement by first clarifying the parameters used in the equations provided. In this case, the length 'L' refers to the size of the box 'a' in both parts i and ii.

For part i, where an electron is enclosed in a box of size a = 10E-10 m, the energy levels can be estimated using the equations provided. The ground state energy (n=1) would be E1 = ((h)^2 ) / (8 * m * (10E-10)^2) = 3.5 x 10^-18 eV. Similarly, the first excited state (n=2) would be E2 = (2^2) * E1 = 4E1 = 1.4 x 10^-17 eV and the second excited state (n=3) would be E3 = (3^2) * E1 = 9E1 = 3.2 x 10^-17 eV.

For part ii, where a 1 g metallic sphere is moving in a box of size a = 10 cm, the energy levels can be estimated using the same equations, but the units need to be converted to joules. The ground state energy (n=1) would be E1 = ((h)^2 ) / (8 * m * (10^-2)^2) = 5.6 x 10^-25 J. Similarly, the first excited state (n=2) would be E2 = (2^2) * E1 = 4E1 = 2.2 x 10^-24 J and the second excited state (n=3) would be E3 = (3^2) * E1 = 9E1 = 5E1 = 1.7 x 10^-24 J.

Moving on to the discussion of the importance of quantum effects for both these systems, it is essential to understand that classical mechanics fails to explain the behavior of particles at the atomic and subatomic level. Quantum mechanics, on the other hand, provides a more accurate description of the behavior of these particles.

In the case of an electron enclosed in a box, quantum effects are crucial in determining the energy levels and the probability of finding the electron at a particular energy level. The size of the box plays a significant role in determining the energy levels, as seen in the equations
 

1. What is a box potential?

A box potential is a model used in quantum mechanics to describe a particle confined within a finite region, also known as a box. The potential energy of the particle is zero within the box and infinite outside of it.

2. How do you calculate the energy levels of a particle in a box potential?

The energy levels of a particle in a box potential can be calculated using the Schrödinger equation and the boundary conditions of the box potential. These energy levels are quantized, meaning they can only take on certain discrete values.

3. What is the relationship between the size of the box and the energy levels of a particle?

The energy levels of a particle in a box potential are inversely proportional to the size of the box. This means that smaller boxes will have higher energy levels and larger boxes will have lower energy levels.

4. Can the energy levels of a particle in a box potential be calculated for any shape of the potential?

No, the energy levels can only be calculated for certain simple shapes of the potential, such as the square or rectangular box potential. More complex potential shapes require more advanced mathematical techniques for calculating the energy levels.

5. How does the number of particles in the box affect the energy levels?

The number of particles in the box does not affect the energy levels of a single particle in the box potential. However, if there are multiple particles in the box, their interactions with each other may affect the energy levels and must be taken into consideration in the calculations.

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