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!

Mass of an accelerated electron by 31 kV

  1. Jun 8, 2013 #1
    1. The problem statement, all variables and given/known data

    My upper grade teacher in physics has lack of intelligence, and she's not in duty to help people. I would like to clear this out here.

    "An electron is accelerated from rest by the electric tension 31.0 kV. Determine the mass of the electron after the acceleration."

    2. Relevant equations

    I've based my procedure from the principles:

    E = qU

    E = mc^2 - m0c^2

    qU = mc^2 - m0c^2

    m0 = is rest mass --> m0 = 9.1093826*10^-31 kg


    3. The attempt at a solution

    m0c^2 = (9.1093826*10^-31)c^2 --> m0 = 8.18751672*10^-14

    q31000 = mc^2 - 8.18751672*10^-14

    mc^2 = 8.68413672*10^-14

    m = 9.66191907*10^-31 kg


    Is this correct?
     
  2. jcsd
  3. Jun 8, 2013 #2

    rude man

    User Avatar
    Homework Helper
    Gold Member

    That looks very good, aside from one typo (" m0 = 8.18751672*10^-14 ").

    Be warned that the "modern" way is to let m = rest mass, then your m = (gamma)*m, gamma = 1/[sqrt(1 - (v^2/c^2)]. m0 is no longer used.

    Don't ask me why.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Mass of an accelerated electron by 31 kV
  1. Electron Acceleration (Replies: 4)

  2. Accelerating electrons (Replies: 7)

Loading...