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Homework Help: Noncentral Elastic Collision

  1. Feb 8, 2010 #1
    1. The problem statement, all variables and given/known data

    First sphere m=0.3 kg collide noncentraly and elasticaly with other sphere of m= 0.35 kg and transfer 79% of first sphere kinetic energy during that collision... u1 is not defined, u2 = 0 m/s

    Ratio between speed after collision v1 : v2 = ??


    2. Relevant equations

    m1u1 + m2u2 = m1v1 + m2v2


    3. The attempt at a solution

    Tryied to make Ek = Ek1 + Ek2

    m1u1 = m1v1 + m2v2

    m2v2 = 0.79 m1u1
    v2 = 0.677 u1

    m1v1 = 0.21 m1u1

    v1= 0.21 u1

    so ratio would be

    v1 : v2 = 0.21u1 : 0.677u1

    so in conclusion

    v1 : v2 = 1 : 3.224



    But I don't know if it's false or right...
     
    Last edited: Feb 8, 2010
  2. jcsd
  3. Feb 8, 2010 #2
    hmmm , your solution doesnt seem logical enough to me .. for example why didnt you use the fact that k=0.mv^2 (or p^2/2m) ??notice what is the relationship between the kinetic energy and the velocity(or momentum) .. how would that change your calculations? .. please try again ..
     
  4. Feb 8, 2010 #3
    Yeah... I got right solution after applying it with kinetic formula...

    Thx nevertheless :)
     
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