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What is the speed at a great distance from the alpha particle

  1. Jun 7, 2015 #1
    1. The problem statement, all variables and given/known data

    An alpha particle has a charge of 2e and is fixed at the origin. A proton is located 2.00x10^-8 m from the alpha particle along the x-axis. When the proton is released, what is its speed at a great distance from the alpha particle

    q = 2e
    r = 2.00x10^-8
    v = ?

    2. Relevant equations

    ɛ = kq / r
    ɛ = ΔV / r
    ΔE = qΔV
    E = kq1q2 / r

    3. The attempt at a solution

    I have no idea how to start this one. As every way I can think of doing it results in missing information that is needed to solve for v. For example when I tried to solve for ɛ and then use it to solve for ΔV, and use that to solve for ΔE, I get stuck with EE = EK but no mass to solve for v.
    Last edited: Jun 7, 2015
  2. jcsd
  3. Jun 7, 2015 #2
    Fixed formatting problem
    Last edited: Jun 7, 2015
  4. Jun 8, 2015 #3


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    What is the PE of the system initially? What is its final PE? Also consider momentum.
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