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Homework Help: Exploding object

  1. Mar 1, 2009 #1
    1. The problem statement, all variables and given/known data
    A 48.0-kg body is moving in the direction of the positive x axis with a speed of 389 m/s when, owing to an internal explosion, it breaks into three pieces. One part, whose mass is 9.5 kg, moves away from the point of explosion with a speed of 385 m/s along the positive y axis. A second fragment, whose mass is 3.0 kg, moves away from the point of explosion with a speed of 413 m/s along the negative x axis. What is the speed of the third fragment? Ignore effects due to gravity.

    M= 48kg
    M1 = 9.5kg
    M2= 3 kg
    M3= 35.5 kg
    Fnet = 0


    2. Relevant equations
    p=mv
    m1v1+m2v2+m3v3=mv0


    3. The attempt at a solution


    been trying to do p = 48*389 = 18672
    then 3*-413 +35.5 * Vx = 18672
    then get vx of 560.87
    then do vy = 9.5*385 + 35.5 vy = -103.02
    then vx^2+ vy^2 = v3^2 and i get 551.33 and its not accepting
     
  2. jcsd
  3. Mar 1, 2009 #2

    AEM

    User Avatar

    Remember the following:

    (1) Momentum before = Momentum After

    (2) Momentum is a vector quantity so the momentum in the x direction must be conserved and separately momentum in the y direction must be conserved.

    (3) Consequently the third piece moves in such a way as to guarantee number (2)
     
  4. Mar 1, 2009 #3
    figured out my error can delete this topic or close whichever you do
     
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