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Homework Help: Rate of change of momentum help please

  1. Jan 13, 2008 #1
    Tried this problem, but not getting it.

    1. The problem statement, all variables and given/known data
    A fire hose sends 2528 gallons of water per minute against a building. The water strikes the building at 28 m/s and does not bounce back. What is the magnitude of the rate of change of momentum of the water?

    2. Relevant equations

    3. The attempt at a solution
    I used the conversion factor of 1 gallon / 3.7856 L and 1 kg / 1 L to find how many kg of water per minute. Then divided by 60 to find how many kg of water per second. I got 159.5 kg of water per second. Then I multiplied by the velocity to get 4466, but I did not get it correct. Am I on the right track or missing something? PLEASE HELP!
    Last edited: Jan 14, 2008
  2. jcsd
  3. Jan 14, 2008 #2

    Shooting Star

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    Homework Helper

    You seem to be doing it correctly. Check your arithmetic once more.
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