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Homework Help: Right hand rule?

  1. Oct 19, 2009 #1
    Assume that a uniform magnetic field is directed into this page. If an electron is released with an initial velocity directed from the left edge to the right edge of the page, which of the following describes the direction of the resultant force acting on the electron?

    I think it would come out of the page using the right hand rule. but then again it says a negative charge, assuming an electron is opposite. so would it go into the page? if anyone could help it would be appreciated thank you!
  2. jcsd
  3. Oct 19, 2009 #2
    When figuring the direction of the magnetic force of an electron, you use the right hand rule, and then take the opposite of what you found. You have that right, but your answer is not right. Look up again how to use the right hand rule, there are two versions that I know of, so I won't say much about that. All I can say is that the electron will not be moving out or into the plane of the page.

    I don't want to give away the answer :)
  4. Oct 19, 2009 #3
    ok so my palm faces east since it goes left to right, my thumb is pointing down. but down would mean positive, so im assuming it goes to the top right?
  5. Oct 19, 2009 #4
    The way I know the right hand rule is to extend your hand in the direction of motion of the particle, curl your four fingers in the direction of the field, and giving a thumbs up gives you the direction of the force.

    So you need your knuckles to point East. Then curl your fingers in the direction of the field, and your thumb would give you the direction of the force and just reverse that because it's an electron and not a proton that we are talking about here.
  6. Oct 20, 2009 #5
    thank you very much!!
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