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Homework Help: Energy conserved?

  1. Nov 22, 2009 #1
    Three marbles have the same mass. Two of them touch each other and are aligned perpendicular to the path of marble 1. The velocity of marble 1 has magnitude v (initial)=10m/s and is directed at the contact point of marbles 2 and 3.

    After the elastic collision what are the speed and direction of the velocity of all marble 1, 2 and 3?

    my attempt:
    v(initial)m = 2mv(subscript2) costheta + v(final)m
    v(initial)^2 m= v(final)^2m/2 + 2vthetha^2*20m/2

    theta= v(subscript2)sintheta-v(subscript3)sintheta
  2. jcsd
  3. Nov 23, 2009 #2


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    Science Advisor
    Homework Helper

    Hi xshezsciencex! :smile:

    This is very confusing. :redface:

    Can you please write it out again, clearly, using the X2 and X2 tags just above the Reply box, and using "i" and "f" for "intial" and "final" (this is normal practice), and this theta: θ.
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