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Homework Help: Pulleys: Why would my calculated work output be higher than my work input?

  1. Apr 13, 2012 #1
    1. The problem statement, all variables and given/known data
    The experiment in my Physics lab today was to determine the mechanical advantage and efficiency of various pulley systems. My calculated work output is higher than my work input, which is causing an abnormally high value for efficiency, and I am attempting to find the source of error. I have attached my data tables and a copy of the lab procedure.

    2. Relevant equations
    work output = (weight of load) * (height lifted)
    work input = (force measured) * (distance moved)

    3. The attempt at a solution
    I guess it would be error in measurement, though I am unsure of how this could have happened.

    Attached Files:

  2. jcsd
  3. Apr 13, 2012 #2


    User Avatar

    Staff: Mentor

    Did you remember to include the mass of any pulleys that moved along with the load in the total load mass? (See step 7 instructions).
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