Calculations with final result in electronvolts

In summary, the question is about determining the units of physical constants when using electronvolts as a unit for energy in a calculation. The relevant physical constants are the elementary charge, Planck constant over 2 pi in eV s, electron mass energy equivalent in MeV, and Bohr magneton in eV/T. It is suggested to use SI units and convert to eV using the elementary charge.
  • #1
barbapapa
2
0

Homework Statement


I have to do a calculation in electronvolt, using physical constants. The final result must be in electronvolts. I can grab the physical constant from scipy (python library). How do I know which constants I can keep in SI units, and which constants I have to transform?

Homework Equations


The relevant physical constants are:
  • elementary charge
  • hbar
  • electron mass
  • bohr magneton

The Attempt at a Solution


[/B]
Use the following physical constants:
  • 'elementary charge' (in coulombs)
  • 'Planck constant over 2 pi in eV s'
  • 'electron mass energy equivalent in MeV' * 10^6 / c^2, where c is in m/s
  • 'Bohr magneton in eV/T'

I am not sure if I have to scale c, and the elementary charge.

Many thanks!
 
Physics news on Phys.org
  • #2
Hello bbpp, :welcome:

You might enlighten us by stating the full problem statement, the relevant equations you plan to use and your attempt at solution. Just like the template suggests you to do ... :rolleyes:

Alternatively do it all in SI and use e (= 1.60217662 × 10-19 coulombs) to convert joules to eV.
 
  • #3
Thank you for your response :)

The question literally is: If we want electronvolt as a unit for energy in the result of a calculation of energy, what must be the units of the physical constants that are defined (instead of SI units).

The answer should be independent of the equations, like SI units can be used for the physical constants to get an answer in joules with any calculation of energy.

So the question is very general and I defined it as much as I can I think :). That is also why I used the physical constants as 'Relevant equations' and my proposed units as 'The attempt at a solution'.
 

What is an electronvolt?

An electronvolt (eV) is a unit of energy that is commonly used in atomic and nuclear physics. It is defined as the amount of energy gained by an electron when it is accelerated through a potential difference of one volt.

How are electronvolts used in calculations?

Electronvolts are used to express the energy of subatomic particles, such as electrons and protons. In calculations, they are used to convert between different units of energy, such as joules or kilojoules, and to determine the energy of a particle in a given system.

What is the significance of using electronvolts in calculations?

Electronvolts are a convenient unit of measurement for small-scale energies, such as those involved in atomic and nuclear processes. They allow for more precise and accurate calculations and are often used in scientific research and experimentation.

How do you convert between electronvolts and other units of energy?

To convert between electronvolts and other units of energy, you can use the conversion factor of 1 eV = 1.602 x 10^-19 joules. To convert from joules to electronvolts, divide the energy value by this conversion factor. To convert from electronvolts to joules, multiply the energy value by the conversion factor.

Can you use electronvolts to compare the energy of different particles?

Yes, electronvolts can be used to compare the energy of different particles. By converting the energy of each particle into electronvolts, you can easily compare their relative energy levels. However, it is important to note that electronvolts only measure the kinetic energy of a particle and not its total energy, which may include potential energy as well.

Similar threads

Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
12
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
616
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
13
Views
1K
  • Introductory Physics Homework Help
Replies
1
Views
2K
  • Introductory Physics Homework Help
2
Replies
35
Views
2K
Replies
9
Views
2K
  • Introductory Physics Homework Help
Replies
15
Views
2K
  • Introductory Physics Homework Help
Replies
2
Views
2K
Back
Top