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Homework Help: What Equation?

  1. Mar 24, 2004 #1
    Hi! I would like to know what equation I would use to figure out this question and why?

    A 10-gram bullet is fired into a 3.0-kilograme block, given that the block a velocity of 30 cm/sec. With what velocity was the bullet fired?

    Thank you for your answer. [?]
  2. jcsd
  3. Mar 24, 2004 #2
    The conservation of momentum:
    [tex]m_1v_1 + m_2v_2 = m_1u_1 + m_1u_2[/tex]
    So that:
    [tex]m_[/tex] - mass of each object
    [tex]v_[/tex] - velocity of each object before impact
    [tex]u_[/tex] - velocity of each object after impact

    Do you need more help or can you figure this out yourself now? :smile:
  4. Mar 24, 2004 #3
    thanx I can figure it out from here.:smile:
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