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Homework Help: Help with magnetism

  1. Apr 19, 2005 #1
    A wire 36m long carries a current of 22 A from east to west. If the maximum magnetic force on the wire at this point is downward (toward the Earth) and has a magnitude of 4.0E-2N, find the magnitude and direction of the magnetic field at this location.

    I have no clue where to start. What does force have to do with it, the given force, I know you're trying to find force.
  2. jcsd
  3. Apr 19, 2005 #2

    What makes you think you're supposed to find a force?
  4. Apr 19, 2005 #3
    well it says find the magnitude and its location, magnetic fields have forces of magnetism
  5. Apr 19, 2005 #4
    hence "magnetic force on the wire at this point is downward (toward the Earth) and has a magnitude of 4.0E-2N"
  6. Apr 19, 2005 #5

    "magnetic fields have forces of magnetism"

    Not really! You need something besides a magnetic field to have a force. What is it?
  7. Apr 19, 2005 #6
    the Force is related to the current and the B field by:
    L is the length of the wire
    I is the currect
    B is the B field

    the bold letter means vector in my notation...
  8. Apr 19, 2005 #7
    thanks i got it now
  9. Apr 19, 2005 #8
    jdavel, your not helping, your complicating the situation, i know what im talking about more then you obviously cause you had no clue where start you just interrogated me
  10. Apr 19, 2005 #9

    Sorry. I was just trying to get you to think about how to solve the problem for yourself. Fortunately for you vincentchan made that unnecesary by handing you the answer.
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