1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: Escape velocity of an electron

  1. Feb 16, 2010 #1
    [tex]\sqrt{}[/tex]1. The problem statement, all variables and given/known data

    What is the escape speed (in m/s) of an electron launched from the surface of a 7.42 cm diameter glass sphere that has been charged to 7.04 nC?

    2. Relevant equations

    u=kqq/r
    KE=1/2MV^2
    UO=KE

    3. The attempt at a solution
    here is what i did
    kqq/r = 1/2mv^2
    solve for v
    v=[tex]\sqrt{}2kqq/rm[/tex]
    i used q = 7.42 square
    and mass of electron = 9.11*10^-31
    and r = 0.0704/2
    ....but still my answer is wrong
     
  2. jcsd
  3. Feb 16, 2010 #2

    collinsmark

    User Avatar
    Homework Helper
    Gold Member

    I believe you have the value of the sphere's charge, and the diameter of the sphere interchanged.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook