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Momentum transfer from a transiting bullet

  1. Jun 19, 2010 #1
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    Last edited: Jun 19, 2010
  2. jcsd
  3. Jun 19, 2010 #2
    Well the energy which it transfers, assuming it's all given in heat/other energy to the target is it's loss in Kinetic Energy;

    [tex] \frac{1}{2}mU^2 - \frac{1}{2}mV^2 [/tex]

    where U is it's initial speed and V is it's final speed after the impact, is that what you're looking for?
     
  4. Jun 19, 2010 #3

    HallsofIvy

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    You appear to be confused between "momentum" and "energy". ft-lbs is a measure of energy, NOT force. Also, knowing how much energy or momentum the bullet lost will NOT tell you the "force applied to the target". you would also need to know either the time or the distance in which the bullet lost momentum or energy. Energy is average force times distance. And "distance" depends upon the substance the target is made of. A person dropping, from a given height, onto a matress will lose exactly the same momentum and energy as a person dropping from the same height onto a steel plate but the force experienced will be a lot less.
     
  5. Jun 19, 2010 #4
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    Last edited: Jun 19, 2010
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