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Homework Help: Gravity's affect on weight in an elevator

  1. Oct 18, 2008 #1
    1. The problem statement, all variables and given/known data

    For this problem I need to figure out how weight changes in a moving elevator. So for example if I had a 20lb dumbbell on a scale and went up 3 floors would the actual weight of the dumbbell change? How would this show on the scale. Then I have the same question except this time the elevator is going down? I really just need the basic concept of how gravity affects the weight. Thanks.

    2. Relevant equations

    No equations needed, its just a theory problem.

    3. The attempt at a solution
  2. jcsd
  3. Oct 18, 2008 #2


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    Science Advisor
    Homework Helper

    Hi bholloway, welcome to PF.

    When the elevator is not moving, which forces are acting on the weight.
    When the elevator is moving upwards, which additional forces are present? Can you describe their magnitude in terms of the acceleration of the elevator? Can you also then compute the total force (hint: Newton's second law) which the block feels (draw a free-body diagram) and the corresponding acceleration (if you want, the "effective" gravity).
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