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Conservation of Momentum in a explosion

  1. Dec 3, 2009 #1
    1. The problem statement, all variables and given/known data
    A firecracker, initially at rest, explodes into two fragments. The first, of mass 14g, moves in the positive x direction at 48m/s. The second moves at 32m/s. Find the mass and direction of its motion.


    2. Relevant equations
    p=mv


    3. The attempt at a solution

    So I know momentum is conserved in this situation. I set m1v1 equal to m2v2 and found the mass of the second fragment to be .041 kg or 41 grams. I think this goes in the negative x direction because the initial momentum is zero and so the sum of all momentums would have to be zero, but I am not sure.
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Dec 3, 2009 #2

    Astronuc

    User Avatar

    Staff: Mentor

    Correct. In the conservation of momentum, the momentum after the explosion = momentum before the explosion. What is the momentum before the explosion?

    Remember that momentum is a vector, which has magnitude and direction. We can have to vectors of the same magnitude, but opposite direction, so the sum is zero.
     
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