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

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SUMMARY

The discussion centers on a physics lab experiment analyzing the mechanical advantage and efficiency of pulley systems. The participant reports a calculated work output exceeding the work input, leading to an unrealistic efficiency value. Key factors contributing to this discrepancy include potential measurement errors and the omission of the mass of moving pulleys from the total load mass, as highlighted in the lab instructions.

PREREQUISITES
  • Understanding of basic physics concepts, specifically work and energy.
  • Familiarity with mechanical advantage in pulley systems.
  • Knowledge of measurement techniques and error analysis.
  • Ability to interpret lab procedures and data tables.
NEXT STEPS
  • Review the principles of mechanical advantage in pulley systems.
  • Learn about common sources of error in physics experiments.
  • Study the impact of load mass on work calculations in pulley systems.
  • Explore methods for accurately measuring force and distance in lab settings.
USEFUL FOR

This discussion is beneficial for physics students, educators conducting lab experiments, and anyone interested in understanding the efficiency of mechanical systems.

veganazi
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Homework Statement


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.

Homework Equations


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

The Attempt at a Solution


I guess it would be error in measurement, though I am unsure of how this could have happened.
 

Attachments

Physics news on Phys.org
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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