What is the wavelength of an electron of 5eV energy?

Click For Summary
SUMMARY

The wavelength of an electron with 5 eV of energy can be calculated using de Broglie's equation, λ = h/p, where h is Planck's constant and p is momentum. The correct approach involves using Planck's constant in Joules per second (J/s) and converting the kinetic energy (K) to Joules by multiplying by the electron charge. The mass (m) of the electron should remain in kilograms, ensuring consistent units throughout the calculation. This method yields accurate results, as demonstrated by other participants in the discussion.

PREREQUISITES
  • Understanding of de Broglie's wavelength equation
  • Knowledge of kinetic energy equations
  • Familiarity with unit conversions between electron volts (eV) and Joules (J)
  • Basic principles of quantum mechanics
NEXT STEPS
  • Study the derivation and applications of de Broglie's equation
  • Learn about unit conversions between eV and Joules in physics
  • Explore the implications of wave-particle duality in quantum mechanics
  • Investigate the significance of Planck's constant in quantum calculations
USEFUL FOR

Students in physics, particularly those studying quantum mechanics, as well as educators and anyone interested in the wave properties of particles like electrons.

ldc1
Messages
1
Reaction score
0

Homework Statement


Calculate the wavelength of an electron which has 5eV of energy.

Homework Equations


de Broglie's equation: lambda=h/p , kinetic energy equation: K=0.5mv^2

The Attempt at a Solution


My attempt: I figured out that using de Broglie's wavelength equation was necessary for this question. but after changing around everything to get lambda = h/(2mK)^1/2, I kept on getting an incorrect answer.
From comparing my methods to others I found that using Planck's constant's value in eV didn't work.
What I really want to know is if I have to change the mass(m) to eV.
The others had used Planck's constant's value in J/s and had multiplied the 2mK by the electron charge ( to change J/s to eV), and it had worked for them.
Why is this?
 
Physics news on Phys.org
Take care with your units.
 

Similar threads

Wavelength = deBroglie Wavelength?
  • · Replies 11 ·
Replies
11
Views
3K
Calculate the wavelength when electron transits.
  • · Replies 2 ·
Replies
2
Views
1K
Electrons impinging on a crystal
  • · Replies 3 ·
Replies
3
Views
2K
Wavelength-stopping potential dependence
  • · Replies 5 ·
Replies
5
Views
2K
De Broglie wavelength of electron and proton
  • · Replies 14 ·
Replies
14
Views
3K
Compare the wavelengths of a photon and an electron
  • · Replies 2 ·
Replies
2
Views
4K
Beam current of positrons and electrons
  • · Replies 5 ·
Replies
5
Views
2K
Can an Electron Be Observed in a Light Microscope?
  • · Replies 10 ·
Replies
10
Views
2K
De Broglie Wavelength Calculation for an Electron with 120 eV Energy
  • · Replies 2 ·
Replies
2
Views
2K
Why does an electron have minimum kinetic energy when its momentum is 2h/λ?
  • · Replies 8 ·
Replies
8
Views
2K