1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Electron Motion

  1. Aug 31, 2004 #1
    The surface charge density on an infinite charged plane is - 2.30 *10^-6 A proton is shot straight away from the plane at 2.20*10^6m/s .



    How far does the proton travel before reaching its turning point?

    I've tried this problem a few times and got 3 different answers...any suggestions?



    Thanks so much for your help.
     
  2. jcsd
  3. Aug 31, 2004 #2

    chroot

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Find the E field due to the charged plane. Use the Lorentz force law to find the force on the proton due to this field. Use Newton's second law to find the acceleration due to the force. Use kinematics to find the zero of velocity.

    - Warren
     
  4. Sep 1, 2004 #3
    We haven't covered Lorentz force law.

    Any more tips?

    Thanks a bunch.
     
  5. Sep 1, 2004 #4

    chroot

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    The Lorentz force law is:

    [tex]\mathbf{F} = q \mathbf{E} + \mathbf{v} \times \mathbf{B}[/tex]

    When the magnetic field is zero, it reduces to just

    [tex]\mathbf{F} = q \mathbf{E}[/tex]

    Given the electric field strength, all you need to do to find the force on a particle is multiply by the particle's charge.

    - Warren
     
  6. Sep 1, 2004 #5
    But what is the E field...its not given...


    Any input?


    Thanks.
     
  7. Sep 1, 2004 #6
    Got it....thanks!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Electron Motion
  1. Electron into motion (Replies: 1)

Loading...