Modern Physics
2nd Edition
ISBN: 9780805303087
Author: Randy Harris
Publisher: Addison Wesley
expand_more
expand_more
format_list_bulleted
Question
Chapter 6, Problem 20E
(a)
To determine
The change in the position and the kinetic energy of a particle, classically.
(b)
To determine
The complete wave function everywhere.
(c)
To determine
The probability of the reflection of the particles.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
This question is for modern physics and wave and particle:
(a) To how small a region must an electron be confined for borderline relativistic speeds – say, 0.05c – to become reasonably likely? (Ans: 3.9×10^−12m ) (b) On the basis of this, would you expect relativistic effects to be prominent for hydrogen’s electron, which has an orbit radius near 10-10? For a lead atom “inner-shell” electron of orbit radius 10-12m?
For ultrarelativistic particles such as photons or high-energy electrons, the relation between energy and momentum is not E = p2/2m but rather E = pc. (This formula is valid for massless particles, and also for massive particles in the limit E » mc2.)
Estimate the minimum energy of an electron confined inside a box of width 10-15 m. It was once thought that atomic nuclei might contain electrons; explain why this would be very unlikely.
Problem 1:
(a) A non-relativistic, free particle of mass m is bouncing back and forth between two perfectly reflecting
walls separated by a distance L. Imagine that the two oppositely directed matter waves associated with this
particle interfere to create a standing wave with a node at each of the walls. Find the kinetic energies of the
ground state (first harmonic, n = 1) and first excited state (second harmonic, n = 2). Find the formula for
the kinetic energy of the n-th harmonic.
(b) If an electron and a proton have the same non-relativistic kinetic energy, which particle has the larger
de Broglie wavelength?
(c) Find the de Broglie wavelength of an electron that is accelerated from rest through a small potential
difference V.
(d) If a free electron has a de Broglie wavelength equal to the diameter of Bohr's model of the hydrogen
atom (twice the Bohr radius), how does its kinetic energy compare to the ground-state energy of an electron
bound to a Bohr model hydrogen atom?
Chapter 6 Solutions
Modern Physics
Ch. 6 - Prob. 1CQCh. 6 - Prob. 2CQCh. 6 - Prob. 3CQCh. 6 - Prob. 4CQCh. 6 - Prob. 5CQCh. 6 - Prob. 6CQCh. 6 - Prob. 7CQCh. 6 - Prob. 8CQCh. 6 - Prob. 9CQCh. 6 - Prob. 10CQ
Ch. 6 - The diagram below plots (k) versus wave number for...Ch. 6 - Prob. 12CQCh. 6 - Prob. 13ECh. 6 - Prob. 14ECh. 6 - Prob. 15ECh. 6 - Prob. 16ECh. 6 - Prob. 17ECh. 6 - Prob. 18ECh. 6 - Prob. 19ECh. 6 - Prob. 20ECh. 6 - Prob. 21ECh. 6 - Prob. 22ECh. 6 - Prob. 23ECh. 6 - Prob. 24ECh. 6 - Prob. 25ECh. 6 - Prob. 26ECh. 6 - Prob. 27ECh. 6 - Prob. 28ECh. 6 - Obtain the smoothness conditions at the...Ch. 6 - Prob. 30ECh. 6 - Prob. 31ECh. 6 - Jump to Jupiter The gravitational potential energy...Ch. 6 - Prob. 33ECh. 6 - Obtain equation (618) from (616) and (617).Ch. 6 - Prob. 35ECh. 6 - Prob. 36ECh. 6 - Prob. 37ECh. 6 - Prob. 38ECh. 6 - Prob. 39ECh. 6 - Prob. 40ECh. 6 - Prob. 41ECh. 6 - Prob. 42ECh. 6 - Prob. 43ECh. 6 - Prob. 44ECh. 6 - Prob. 45ECh. 6 - Prob. 46ECh. 6 - Prob. 47ECh. 6 - Prob. 48ECh. 6 - Prob. 49ECh. 6 - Prob. 50ECh. 6 - Prob. 51CECh. 6 - Prob. 52CECh. 6 - Prob. 53CECh. 6 - Prob. 54CECh. 6 - Prob. 56CE
Knowledge Booster
Similar questions
- The normalized wavefunction of an electron in a linear accelerator is ψ = (cos χ)eikx + (sin χ)e–ikx, where χ (chi) is a parameter. (a) What is the probability that the electron will be found with a linear momentum (a) +kħ, (b) −kħ? (c) What form would the wavefunction have if it were 90 per cent certain that the electron had linear momentum +kħ? (d) Evaluate the kinetic energy of the electron.arrow_forward(d) Prove that for a classical particle moving from left to right in a box with constant speed v, the average position = (1/T) ff x(t) dt = L/2, where T L/v is the time taken to move from left to right. And = : (1/T) S²x² (t) dt L²/3. Hint: Only consider a particle moving from left x = 0 to right x = L = and do not include the bouncing motion from right to left. The results for left to right are independent of the sense of motion and therefore the same results apply to all the bounces, so that we can prove it for just one sense of motion. Thus, the classical result is obtained from the Quantum solution when n >> 1. That is, for large energies compared to the minimum energy of the wave-particle system. This is usually referred to as the Classical Limit for Large Quantum Numbers.arrow_forwardA 4.90g Particle confined to a box of length L has a speed of 4.70mm/s a) lalhat is the classical Kinetic energy of Particle? the b) If the energy of the first excited State (n=2) is equal to the Kinetic energy found in part (a), what is the value Note: Answer must be in mi L? of c) Is the result found in part (b) realistic ? Explain.arrow_forward
- Suppose a duck lives in a universe in which h=2πJ⋅s h=2πJ⋅s. The duck has a mass of 2.00 kg and is initially known to be within a pond 1.00 m wide. (a) What is the minimum uncertainty in the component of the duck’s velocity parallel to the pond’s width? (b) Assuming this uncertainty in speed prevails for 5.00 s, determine the uncertainty in the duck’s position after this time interval.arrow_forward(a) Calculate the minimum uncertainty in momentum (expressed in MeV/?) for a proton confined to a nucleus of diameter 5.0 fm. (1 fm = 1 * 10-15 m). (b) A proton (rest mass 938.3 MeV/?2) in a nucleus of radius 6.0 fm has a kinetic energy of 5.6 MeV. If the proton were represented by a de Broglie wave, how many wavelengths could fit across the diameter of that nucleus? (1 fm = 1 * 10-15 m). (c) Electrons (rest mass 0.51 MeV/?2) moving with a speed of 1.60 × 105 m/s are described by a wave packet of width 2.65 nm. What range of values will most likely result from a measurement of the speed of the electrons? Please use:ℎ? 1240 eVnmℏ? 197 eVnmarrow_forwardPlease asaparrow_forward
- An electron is revolving around a proton in a circular orbit of radius r. The proton is assumed to be stationary. The total energy of this system is p? 1 e? E 2m 4TE, r where p and m denote the momentum and mass of the electron, respectively. Take the radius r to be an estimate of the uncertainty in position Ar, and the uncertainty in momentum Ap to be an estimate of p. Suppose that ArAp = ħ when the system is in the ground state. Show that the ground state energy is given by 1 me4 e 8h? E1 Give the numerical value for E, in electronvolts. Discuss if your results are consistent with Bohr's model for the hydrogen atom.arrow_forwardA 4.00-g particle confined to a box of length L has a speed of 1.00 mm/s. (a) What is the classical kinetic energy of the particle? (b) If the energy of the first excited state (n = 2) is equal to the kinetic energy found in part (a), what is the value of L? (c) Is the result found in part (b) realistic? Explain.arrow_forwardA Proton Of Energy 250keV is scattered at an angle 120° by a stationary free electron,Then Find The Energy Of The Scattered Photon (in MeV)?arrow_forward
- A particle moves through a region with a constant potential energy V0. Show that the wavefunction Ψ(x) = A exp (−αx), with α a real number, is a solution of the time-independent Schr¨odinger equation. What isthe total energy of such a particle?arrow_forwardBe-H is given -ur In the Born approximation, the scattering amplitude f(e) for the Yukawa potential V(r) = by: (in the following b = 2k sin E = h?k? / 2m) 2 | 2mß 2mß 2mß 2mB (a) (b) (c) (d) h? (u? +b?)arrow_forwardAn unknown moving ion is confined in a OD nanomaterial in which all three dimensions are equals to 5 nm. Estimate with what accuracy its velocity and energy can be measured (given mass of the ion is 4.8×10 26 kg)?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Modern PhysicsPhysicsISBN:9781111794378Author:Raymond A. Serway, Clement J. Moses, Curt A. MoyerPublisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningClassical Dynamics of Particles and SystemsPhysicsISBN:9780534408961Author:Stephen T. Thornton, Jerry B. MarionPublisher:Cengage Learning
- University Physics Volume 3PhysicsISBN:9781938168185Author:William Moebs, Jeff SannyPublisher:OpenStaxPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning
Modern Physics
Physics
ISBN:9781111794378
Author:Raymond A. Serway, Clement J. Moses, Curt A. Moyer
Publisher:Cengage Learning
Principles of Physics: A Calculus-Based Text
Physics
ISBN:9781133104261
Author:Raymond A. Serway, John W. Jewett
Publisher:Cengage Learning
Classical Dynamics of Particles and Systems
Physics
ISBN:9780534408961
Author:Stephen T. Thornton, Jerry B. Marion
Publisher:Cengage Learning
University Physics Volume 3
Physics
ISBN:9781938168185
Author:William Moebs, Jeff Sanny
Publisher:OpenStax
Physics for Scientists and Engineers: Foundations...
Physics
ISBN:9781133939146
Author:Katz, Debora M.
Publisher:Cengage Learning