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Homework Help: Potential Energy and Work done to lift object distance h

  1. May 23, 2013 #1
    Potential Energy and Work done to lift object distance "h"

    The amount of energy needed to power a 0.10 kW bulb for 12 minutes would be sufficient to lift a 1 kg object how high?

    Power = work/time
    PE = mgh

    First I converted kw to watts which is 100 watts. Then converted minutes to seconds = 720 seconds.
    I found the work done by the lightbulb:

    power = work/time
    100 = w/720
    w = 72,000 joules

    Then I plugged that into potential energy(not sure if you can do that), I solved for h using 9.8 for gravity and 1 kg for mass

    PE = mgh

    72,000 = (1)(9.8)h

    h = 7347 meters

    That number seems a bit high
  2. jcsd
  3. May 23, 2013 #2


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    That looks good to me.
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