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Homework Help: Physics question, velocity

  1. Nov 14, 2007 #1
    Physics question, velocity....

    1. The problem statement, all variables and given/known data
    A rifle with a weight 19N fires a .0067kg bullet with a speed of 124m/s. The acceleration of gravity is 9.81 m/s2. Find the recoil speed of the rifle. Answer in units of m/s.


    2. Relevant equations
    F=ma, F= m(change in velocity/change in time), Vfinal=Vinitial+at
    I really don't know..... I don't know any equations with force and velocity.


    3. The attempt at a solution

    19=(.0067)+(9.81x124)V
     
  2. jcsd
  3. Nov 14, 2007 #2

    nrqed

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    Have you seen momentum? This problem is done by imposing conservation of momentum. The value of g is only given so thatyou may figure out the mass of the rifle (they give the weight, not the mass)
     
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