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Homework Help: Problem using Work

  1. Oct 13, 2009 #1
    1. The problem statement, all variables and given/known data

    A 50kg woman climbs a 3000m mountain high. a) how much work does she do against the gravitational forces? b) a kilogram of fat supplies 3.8 x 10^7 J of energy. If she converts fat into mechanical energy with a 20% efficiency rate, how much fat will she consume in the climb?

    2. Relevant equations

    E= Einitial + Wa or K + U = Kinitial + Uinitial + Wa

    K= 1/2mv^2 and U=mgh

    thanks.. I really appreciate it.
  2. jcsd
  3. Oct 13, 2009 #2


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    Homework Helper

    Work done against the gravitational force is stored as the potential energy. From the relevant equation given by you can find this energy.
    Find 20% of that energy. From that find the fat consumption.
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