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course phy 231
Brief pendulum experimentUses: washer, thread, analog clock, ruler or meter stick
Construct a pendulum using washer and thread. Make 1-minute counts for pendulum lengths (measured from the position at which the thread is held to the center of the washer) equal to three different lengths:
• the the distance from your wrist to your fingertips
• the distance from your elbow to your fingertips
• the distance from your shoulder to your fingertips
Be sure to measure the length of each pendulum you time.
Report the pendulum lengths and the corresponding numbers of counts:
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Wrist to fingers: 8 inches, 63 full swings in 1 minute
Elbow to fingers: 18 inches, 41 full swings
Shoulder to fingers: 28 inches, 35 full swings
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Analysis:
Graph your 1-minute count vs. length, and sketch a smooth curve representing the trend of your data.
Using your graph estimate the number of counts for a pendulums of length 52 cm, and another of length 13 inches. Estimate also the lengths corresponding to pendulum counts of 30 and 50.
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Determine the period of each of your three pendulums, i.e., the time required to complete 1 oscillation. A oscillation is from extreme point through equilibrium to opposite extreme point.
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Sketch a graph of period vs. length, showing your three points, and sketch a smooth curve to fit your graph.
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Use your graph to estimate the period of a pendulum whose length is 26 cm, and also the length for which the period would be 1.2 seconds.
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What is the uncertainty in the number of counts made, and to what do you attribute the uncertainty?
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What is the approximate average percent uncertainty in your counts?
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Do your sources of uncertainty result in the same expected percent uncertainty for all counts?
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Data look good. I've appended instructions and questions for analysis.
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