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: Determine the ratio of the electron's speed

  1. Jul 15, 2005 #1
    Determine the ratio of the electron's speed over that of the proton at the end of their respective trajectories? KE = 5.29keV

    My question is do I use the kinetic energy to get velocity of electron then proton separately, and afterwards divide the results to obtain the ratio?
  2. jcsd
  3. Jul 15, 2005 #2
    That's what I would do.
  4. Jul 15, 2005 #3
    electron: m, v
    proton: M, u

    mv²/2 = Mu²/2
    mv² = Mu²
    v²/u² = M/m
    v/u = sqrt(M/m) = sqrt(1836) = 42.85

    (valid for v << c)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook