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: Speed of proton and alpha particle

  1. Jan 22, 2014 #1
    1. The problem statement, all variables and given/known data
    An alpha particle (4 times the mass of a proton with a charge of +2e) is at rest 1.0 * 10^-12 m from a stationary proton. The 2 particles immediately move apart. Find the speed of each particle when they are infinitely far from each other.

    2. Relevant equations

    Electrical Energy = kq1q2/r
    Kinetic Energy = 0.5mv^2

    3. The attempt at a solution

    I used the equation kq1q2/r to find the potential energy of the system and converted the potential energy into 0.5mv^2 to solve for the velocity. I am not sure that I have the right answer.
  2. jcsd
  3. Jan 22, 2014 #2


    User Avatar
    Homework Helper

    right approach .... but which one is moving faster? how many times as fast is it?
    what fraction of the total KE does the fast one have?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted