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Homework Help: Work and Energy of a climbing person

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

    How many meters above the ground would a person ( 188.3 lb ) have to climb to gain 3 kilojoules ( 3000 joules ) of potential energy. We usually measure our weight ( W = mg ) in pounds. For conversions, you may need to know that 1 pound is equal to 4.448 Newtons.

    2. Relevant equations

    PE = MGH

    3. The attempt at a solution
    I used this to solve for h...not working! please help!
  2. jcsd
  3. Oct 1, 2009 #2

    Andrew Mason

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    Homework Helper

    PE = Work done against gravity = [itex]\vec F \cdot \vec d = (mg)h = [/itex] weight x height.

    You do not have to use g explicitly here since you are given the weight, in Newtons, of one pound of matter. The person weighs 188.3 times that or, as you have found, 837.558 N.

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