Chapter 7: Problem 8
Can we measure the energy of a free localized particle with complete precision?
Short Answer
Step by step solution
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none}
Learning Materials
Features
Discover
Chapter 7: Problem 8
Can we measure the energy of a free localized particle with complete precision?
These are the key concepts you need to understand to accurately answer the question.
All the tools & learning materials you need for study success - in one app.
Get started for free
A wave function of a particle with mass \(m\) is given by $$\psi(x)=\left\\{\begin{array}{cl} A \cos \alpha x, & -\frac{\pi}{2 \alpha} \leq x \leq+\frac{\pi}{2 \alpha} \\ 0, & \text { otherwise } \end{array}\right.$$ where \(\alpha=1.00 \times 10^{10} / \mathrm{m} .\) (a) Find the normalization constant. (b) Find the probability that the particle can be found on the interval \(0 \leq x \leq 0.5 \times 10^{-10} \mathrm{m}\). (c) Find the particle's average position. (d) Find its average momentum. (e) Find its average kinetic energy \(-0.5 \times 10^{-10} \mathrm{m} \leq x \leq+0.5 \times 10^{-10} \mathrm{m}\)
Using the quantum particle in a box model, describe how the possible energies of the particle are related to the size of the box.
A particle of mass \(m\) is confined to a box of width L. If the particle is in the first excited state, what are the probabilities of finding the particle in a region of width \(0.020 L\) around the given point \(x:\) (a) \(x=0.25 L ;\) (b) \(x=0.40 L ;(\mathrm{c}) x=0.75 L ;\) and (d) \(x=0.90 L\)
Assume that a proton in a nucleus can be treated as if it were confined to a one-dimensional box of width 10.0 fm. (a) What are the energies of the proton when it is in the states corresponding to \(n=1, n=2,\) and \(n=3\) ? (b) What are the energies of the photons emitted when the proton makes the transitions from the first and second excited states to the ground state?
Consider an infinite square well with wall boundaries \(\begin{array}{llllll}x=0 & \text { and } & x=L & \text { Show } & \text { that } & \text { the function }\end{array}\) \(\psi(x)=A \sin k x \quad\) is the solution to the stationary Schrödinger equation for the particle in a box only if \(k=\sqrt{2 m E} / \hbar .\) Explain why this is an acceptable wave function only if \(k\) is an integer multiple of \(\pi / L\)
What do you think about this solution?
We value your feedback to improve our textbook solutions.