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Homework Help: Physics - Edexcel unit 4

  1. Feb 13, 2012 #1
    1. The problem statement, all variables and given/known data

    A radium nucleus decays by emitting an alpha particle. The speed of the recoiling
    nucleus is small compared to the speed of the alpha particle. This is because the:

    A force acting on the recoiling nucleus is smaller than the force acting on the
    alpha particle
    B momentum is mainly concentrated in the alpha particle
    C momentum of the recoiling nucleus is smaller than the momentum of the
    alpha particle
    D recoiling nucleus has a much larger mass than the alpha particle

    why is it D?

    http://www.edexcel.com/migrationdoc...E January 2010 - ER/6PH04_01_pef_20100310.pdf

    Look at question 7)

    for part (i) why is it C and

    for part (iii) we were NOT told that O was stationairy so why is it D?

    2. Relevant equations

    3. The attempt at a solution
    ok so for q3)
    there is no way to conclude any of them
    A: we don't know the accelerations
    B: how much faster is it moving?
    C: again we don;t know exact speeds
    D: true but why relevant?

    for Q7)
    i) I would have said none of them can be KNOWN
    but I would say X and Y have the same charge as they move in the same direction

    ii) I got

    we are not told if O is stationairy or not?
    Last edited: Feb 13, 2012
  2. jcsd
  3. Feb 13, 2012 #2
    ok so I get the first one. momentum is conserved and the forces are the same due to netwon 3
    but for Q7 in the paper I don't undertand i or iii)
  4. Feb 13, 2012 #3
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