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Homework Help: Help please, motion of charged particle in mag field

  1. Mar 13, 2005 #1
    A proton moves in a circular orbit perpendicular to a uniform magnetic field of 0.758T. Find the time it takes the proton to make one pass around the orbit.

    Just need someone to help me start off. All I have is that the B=0.758T, q=1.6x10^-19C and m=1.67x10^-27kg. What formulas do I need to use to find t?
    Thanks
     
  2. jcsd
  3. Mar 13, 2005 #2

    dextercioby

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    U can prove (i advice u to do it) that

    [tex] r=\frac{mv}{qB} [/tex]

    Exploit the connection beteen T,v & r.

    Daniel.
     
  4. Mar 13, 2005 #3
    hmm so r=mv/qB is derived from mv^2/r=qvB. I got r=(1.4x10^-8)v. the thing is.. i dont kno the relationship between the time, radius and velocity. Do i use r to find the circumference and multiply that by the velocity? im not really sure..
    thanks for the response
     
  5. Mar 13, 2005 #4

    dextercioby

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    Yes,that "v" is the constant tangential speed.Multiplied with the period should give exactly 2\pi r...

    Daniel.
     
  6. Mar 13, 2005 #5
    ok i got the correct answer now.. THanks a lot!! :D
     
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