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Homework Help: Electrons in a beam of televison tube

  1. Mar 18, 2005 #1
    Ive got a question where I have to find the acceleration of a single electron due to the magnetic field. Now here is what I did. I tired to find Velocity using KE = .5mv^2. Solving for v. Then knowing that F=qvB and F=ma I made the equation qvb/m=a. But I cant get this to work. Is there some thing that I'm doing wrong. This is a related question with the numbers in it:
    I think my problem is with converting uT to T for the electric field. And converting my 24 keV to J. Anyone have some help. Thanks.
  2. jcsd
  3. Mar 18, 2005 #2

    Andrew Mason

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    Your approach is correct except that the force is:

    [tex]\vec F = q\vec v \times \vec B = qvBsin\theta[/tex]

    What is the angle of [itex]\vec v [/itex] to the magnetic field?[itex]\vec B[/itex] Why not show us what you have done? It is a little hard to figure out where you may have gone wrong otherwise.

  4. Mar 18, 2005 #3
    Well, the vertical component of B was given in the problem, so I don't think you need to do the cross product. You're probably just having problems with unit converstions.
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