Relativistic Calculations for De-Broglie Wavelength

Click For Summary
SUMMARY

The forum discussion centers on calculating the De Broglie wavelength of electrons and protons, specifically identifying the energy threshold at which non-relativistic calculations yield a 5% error. The participants highlight two approaches to the problem, with the second approach correctly utilizing relativistic principles, emphasizing that De Broglie wavelength is dependent on momentum rather than solely on kinetic energy. The consensus is that non-relativistic methods become inaccurate at higher energies, particularly for particles approaching relativistic speeds.

PREREQUISITES
  • Understanding of De Broglie wavelength and its formula
  • Familiarity with relativistic mechanics
  • Knowledge of momentum and kinetic energy relationships
  • Basic principles of quantum mechanics
NEXT STEPS
  • Study the derivation of the De Broglie wavelength formula in both non-relativistic and relativistic contexts
  • Learn about relativistic momentum and its implications in particle physics
  • Explore the differences between kinetic energy calculations in classical and relativistic mechanics
  • Investigate the significance of the rest energy in relativistic equations
USEFUL FOR

Students and educators in physics, particularly those focusing on quantum mechanics and relativistic physics, as well as researchers interested in particle behavior at high energies.

IWantToLearn
Messages
95
Reaction score
0

Homework Statement


At what energy will a non-relativistic calculation of the De Broglie wavelength of an electron be in error by 5%? What is this energy for a proton? Comment on your results.

Homework Equations


I have two (seemed to be) logical answers for this question, but with different values

how to resolve this, there must be at least one wrong answer

i need a resolution [/B]

The Attempt at a Solution


Solution 1
Untitled.png

Solution 2
Untitled2.png
 
Physics news on Phys.org
The second approach has the right relativistic de-Broglie wavelength. It depends on the momentum, not on "the energy above the rest energy plugged into the nonrelativistic expression".
 
As far as i understand, there is nothing in the first approach states that the De-Broglie wavelength depend in anything but the momentum
in the first approach i replaced the momentum by the kinetic energy, and this is a valid replacement

please explain your point
 
You replaced momentum by the kinetic energy in nonrelativistic mechanics. It won't give the right result for relativistic speeds.
 
  • Like
Likes   Reactions: IWantToLearn

Similar threads

  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 14 ·
Replies
14
Views
3K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 11 ·
Replies
11
Views
3K
Replies
4
Views
2K
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 8 ·
Replies
8
Views
4K
  • · Replies 3 ·
Replies
3
Views
2K