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Homework Help: Energy and explosions

  1. Mar 13, 2007 #1
    1. The problem statement, all variables and given/known data
    An explosion breaks an object into two pieces, one of which has 1.5 times the mass of the other. If 7400 J were released in the explosion, how much kinetic energy did each piece acquire?


    2. Relevant equations
    Momentum?
    Kinetic Energy?


    3. The attempt at a solution
    I used all types of formulas having to do with energies and momentum and nothing gave me an answer.
     
  2. jcsd
  3. Mar 14, 2007 #2
    Use conservation of linear momentum along the horizontal since all the forces are internal (the energy that the explosion released was stored inside the projectile/object).

    You know that m1v1+m2v2=0. And are given that m1=1.5m2.
    Also, the total energy released in the explosion is converted into kinetic energy (you have to assume that), so [tex]0.5m_1v_1^2+ 0.5m_2v_2^2=7500[/tex]. Solve for v1/v2 and find the KE of each piece.
     
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