• Support PF! Buy your school textbooks, materials and every day products Here!

Problems involving electromagnetism

  • Thread starter 21385
  • Start date
  • #1
33
0

Homework Statement


In problems involving electromagnetism it is often convenient and informative to express answers in terms of a constant, x, which is a combination of the Coulomb constant, k, the charge of an electron, e, and H=h/(2pi), with h being Planck's constant. For instance, the lowest energy that a hydrogen atom can have is given by E=-(0.5)(x^2)m(c^2), where m is the mass of the electron and c is the speed of light. Which of the following is the correct expression for x?
(HINT: Non-relativistic kinetic energy is (0.5)m(v^2), where v is the speed.)

a) (k(e^2))/(Hc)
b) H/(k(e^2)c)
c) (k(e^2)H)/c
d) (k(e^2)c)/H


Homework Equations


E=hf
E=m(c^2)
E=(1/2)m(v^2)


The Attempt at a Solution


I really don't know what they are asking for or what formula they are referring. Can someone help? Thanks.
 

Answers and Replies

  • #2
261
2
Analyze the units of the various answers (dimensional analysis) in order to get the given expression to be in joules.

You can avoid solving for the energy levels of the hydrogen atom if you use dimensional analysis.
 

Related Threads on Problems involving electromagnetism

  • Last Post
Replies
9
Views
3K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
3
Views
7K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
7
Views
2K
  • Last Post
Replies
19
Views
2K
  • Last Post
Replies
1
Views
1K
Replies
4
Views
2K
Top