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Homework Help: Collisions problem!

  1. Oct 2, 2011 #1
    1. The problem statement, all variables and given/known data

    An unstable nucleus of mass 1.70 10^-26 kg, initially at rest at the origin of a coordinate system, disintegrates into three particles. One particle, having a mass of m1 = 5.40 10^-27 kg moves in the positive y-direction with speed v1 = 7.20 106 m/s. Another particle, of mass m2 = 8.40 10^-27 kg moves in the positive x-direction with speed v2 = 4.40 106 m/s. Find the velocity of the third particle. (Assume that mass is conserved in this process. Indicate the direction with the sign of your answer.)

    2. Relevant equations

    3. The attempt at a solution
    I found the mass of the third particle 1.7x10^-27-(5.4x10^-27+8.4x10^-27)=3.2x10^-27
    I split it into X and Y components, and starting with the y i plugged into the equjation: 1.7X10^-26(0)=5.4x10^-27(7.2x10^6) + 0 + 3.2x10^-27v2f
    I would repeat the same process for the x direction, but i tried entering this response into the y answer spot and it was incorrect. Please help me see what I did wrong and how to figure it out!
  2. jcsd
  3. Oct 2, 2011 #2

    Doc Al

    User Avatar

    Staff: Mentor

    Your method is fine, just redo the calculation. Mind your exponents.
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