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Motion of Charged Particles

  1. Jul 19, 2010 #1
    1. The problem statement, all variables and given/known data

    1) Calculate the value of B_z needed for an electron with a speed of 6X10^5 m/s to be deflected to the right in acirle of radius 3cm.

    2) Calculate the value of E_x needed for an alpha particle with a speed of 6X10^5 m/s to be deflected to the right in a circle of radius 3cm.

    3) Calculate the value of E_x needed for an electron with a speed of 6X10^5 m/s to be deflected to the right by 3 cm.

    4) Calculate the value of E_x needed for any particle with a speed of 6X10^5m/s to be deflected in a magnetic field of .0005T.

    5) Calculate the radius of the circle in this helix.


    2. Relevant equations

    r= mv/QBz

    Ex = vB


    3. The attempt at a solution

    So problems 1 and 2 are straight forward plug and play. Got those answers to be 1.14E-4 T and .415 T respectively. Problem 4 is also plug and play to come out to 300 N/C.

    Where I get out of what is on problem 3 and 5. Any help/equations to get me started? I hate to look like I haven't tried to solve there I just don't know where to go with these. Just need some help along the yellow brick road.
     
  2. jcsd
  3. Jul 20, 2010 #2
    Anyone have any ideas?
     
  4. Jul 22, 2010 #3
    It doesn't make sense.

    Apart from the peculiar mix of Cartesian directions and left/right, I assume the x direction to mean the original direction of travel.
    In which case for part 3 the field E_x would be along that same direction and would merely impart additional acceleration. To the right?! - it's meaningless.

    I don't see how you answer 4 so confidently either. It just says 'to be deflected' How much? are we to assume it's the same 3cm radius?

    The first two parts are reasonable and fairly trivial questions - but the rest of it is garbage.

    Is there a diagram? Is that what's missing?
     
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