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Homework Help: I'm stumped lol

  1. Nov 15, 2004 #1
    Two frictionless discs on air table, initially at rest, are driven apart by an explosion with velocities of 9.0m/s and 5.0m/s what is ratio of masses?
    how do i get masses if i don't know Momentum ? +__+
     
  2. jcsd
  3. Nov 15, 2004 #2
    m1u1=m2u2 Since we want the ratio of m1 and m2 we make m2=m1*k(a constant)
    m1(9m/s)=m1*k*5m/s
    k=9/5 So the ratio of the two masses is that the 1st has the 5/9 of the seconds mass
     
  4. Nov 15, 2004 #3
    the answer key says its 0.36 .. why's that?
     
  5. Nov 15, 2004 #4
    I have no idea...maybe they made a mistake or I did one....lol
     
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