The purpose of this lab is to derive equations to determine the acceleration of two masses using a derived equation. At the conclusion of this lab we will also determine difference between findings.
Theory
Atwood'd Device was developed in 1874 by George Atwood to experiment with the mechanical laws of motion and with constant acceleration. In theory, the pulley used is relatively friction less so the acceleration should be able to be easily calculated.
Free Body Diagram (above)
Derived equation for finding acceleration
Experimental Technique
During the experimentation portion of the lab, we used pulleys, string, weights, extension rods, a photo gate, and a clamp.
The weight in each measurement was changed by keeping a common total weight between the two hanging asses but adding and subtracting from each. We measured acceleration using two different methods. The first method used was plugging amounts into the equation for acceleration that we derived. The second method was finding the average acceleration using the photo gate program.
Data
The predicted acceleration was found using the derived acceleration equation while the actual acceleration was found using the photo gate. Percent difference was found using the percent difference equation.
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Analysis
Sample Calculation
Conclusion
Overall, the lab felt as though it was successful. We used 10 data sets to show a larger span of measurements. Between the data sets, the amount of difference varied greatly. This could be due either rounding error or human error. The human error was most likely present while releasing the heavier mass or calculating the span of the movement in the phot gate program.
References
Wikipedia - Atwood machine. (2014, November 15). Retrieved November 26, 2014, from http://en.wikipedia.org/wiki/Atwood_machine