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Homework Help: Potential Energy

  1. Dec 3, 2005 #1
    Question: There is a 1000kg cart on the top of 80m hill which it rolls down onto a smaller hill of unknown height with a velocity of 20m/s. What is potential energy and height of its current position? What is the kinetic energy, potential energy, and velocity when it reaches a flat surface? Assume no losses to friction and with a g of 10m/s. Thanks a lot
  2. jcsd
  3. Dec 3, 2005 #2


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    Science Advisor
    Homework Helper

    Show us some of your work!
  4. Dec 4, 2005 #3
    So far I have the four answers for when they are at the top of the 80m hill before moving. K.E.=0 P.E.= 800000J, V=0, H=80m. I've calculated their kinetic energy to be 200000J at the smaller hill with the information provided(v=20m/s) I would appreciate it if someone could tell me how to go about doing this question.
  5. Dec 4, 2005 #4


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    energy is conserved So

    (top) mgh1 = mgh2 + 1/2mv^2 (smaller hill)

    you know everything but "h2", use algebra to find "h2"
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