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

by veganazi
Tags: calculated, input, output, pulleys, work
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Apr13-12, 12:51 PM
P: 13
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
File Type: xls pulley lab tables.xls (33.0 KB, 6 views)
File Type: pdf pulleys procedure.pdf (102.1 KB, 4 views)
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Apr13-12, 01:21 PM
P: 11,838
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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