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Homework Help: Conservation of momentum: vertical shot

  1. Jun 28, 2010 #1
    1. The problem statement, all variables and given/known data
    A 0.028 kg bullet is fired vertically at 165 m/s into a 0.15 kg baseball that is initially at rest. How high does the combined bullet and baseball rise after the collision, assuming the bullet embeds itself in the ball?


    2. Relevant equations
    mv + mv = mv + mv


    3. The attempt at a solution
    m1 = 0.028 kg
    v1 = 165 m/s
    m2 = 0.15 kg
    v2i = 0 m/s

    (0.028 kg)(165 m/s) + (0.15 kg)(0 m/s) = (0.178 kg) vf
    vf=25.96 m/s

    v2=vo2 - 2gy
    25.962 = - 2(9.8 m/s2)y
    y=693.5m
     
  2. jcsd
  3. Jun 28, 2010 #2

    rock.freak667

    User Avatar
    Homework Helper

    That does not give 693.5 m. Recheck it.
     
  4. Jun 28, 2010 #3
    ah, i subtracted instead of divided. man, i feel silly now! thank you! when I divided, i got 34.4m, which is correct :)
     
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