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Homework Help: Finding the mass of a hockey puck - inertia

  1. Oct 28, 2007 #1
    Finding the mass of a hockey puck - inertia!!!

    An ice hockey puck slides along the ice at 12m/s. A hockey stick delivers an impulse of 4.5 kg * m/s, causing the puck to move off in the opposite direction with the same speed. What is the mass of the puck. Friction and drag are negligible.

    Any Ideas? I am completely lost.

  2. jcsd
  3. Oct 28, 2007 #2


    Yes my units are correct. I was skimming over my notes from class and I belive we have to use the ∆px=jx=area under the curve equation

    to find the ball's momentum:

    m(vf)x-m(vi)x but then I dont have "m" this whole thing is equal to jx

    and then the area under the curve

    jx=fmax • ∆time

    but I have jx and the velocities, but not the mass or the fMax
  4. Oct 28, 2007 #3
    oh sorry, you're actually ahead of me :-p hopefully someone will be able to help you tonight.
    Last edited: Oct 28, 2007
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