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Homework Help: Calculate the average net force acting on the bullet

  1. Oct 29, 2006 #1
    I have a physics problem and are woundering if someone can please help me!o:)
    Here's the problem: A bullet of mass 20 g strikes a fixed block of wood at a speed of 320 m/s. The bullet embeds itself in the block of wood, penetrating to a depth of 6.0 cm. Calculate the average net force acting on the bullet while it is being brought to rest. (1.7 x 14^4 N)

    would have been nice with the whole calculation.
    Thanks! :!!)
  2. jcsd
  3. Oct 29, 2006 #2


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    Trythe work-energy theorem, which states
    [tex] W_{net} = \Delta KE[/tex]
    What is the initial kinetic energy of the bullet just before it penetrates the wood? What is its final kinetic energy when it comes to a stop in the wood? What is the difference between the two energies? What is the definition of work?
  4. Nov 1, 2006 #3
    Alternatively, you can use kinematics to determine the acceleration of the bullet (vf^2 = vi^2 + 2ad), then use Newton's 2nd Law to determine the force (F = ma).
  5. Nov 2, 2006 #4
    thank you very much! =)
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