Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Radii for a circular path of a proton.

  1. Sep 24, 2008 #1
    1. The problem statement, all variables and given/known data

    Find the radius of the circular path described by a proton moving at 15 in a plane perpendicular to a 400- magnetic field.

    2. Relevant equations

    I used the Eqn: r=mv/qB
    So (1.67e-27)(15ooom/s)/(1.60e-19)(400) and I go 6.265e-2 m

    but the answer is in mm so im i correct to just say 6.265e-5
    since mm is e-3 and its alrdy e-2m
    is my answer even right though?
  2. jcsd
  3. Sep 24, 2008 #2
    I don't know the magnitude of the quantities for your problem, so I can't say if your answer is right. You didn't specify them; 400 T, 400 mT, etc.?

    Anyways, your equation is correct; shift your decimal point one position to the right and you will get 62.65e-3 m, which is equivalent to 62.65 mm.

    To get help quickly, try to be as clear as possible with the problem description. It takes extra time on your part, but don't forget that those who respond to your question must sacrifice their time as well to help you.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook