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Phy 121
Your 'cq_1_01.2' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
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How accurately do you think you can measure the time between two events using the TIMER program?
answer/question/discussion: ->->->->->->->->->->->-> sion (start in the next line):
In our first encounter with the TIMER program, we determined that the TIMER measured time in intervals of 1/64 seconds or 0.015625 seconds. From the text I understand that a ruler with mm gradations can measure to within 1 mm or +/- 1mm, the same logic would lead us to believe that the timer can measure time accurately to within +/- 0.015625 seconds. ??? This makes me wonder, since it could be + .015625, or -.015625, do we need to double that in terms of accuracy, since +/- -.015625 gives us a spread of .03125???
It also begs the question ???How do we handle significant figures when expressing accuracy. .015625 isn’t really derived from other measurements with significant figures. I get the feeling the 1 and the 64 in 1/64 don’t count.???
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The quantity with the +- is half the spread of the data.
So it would be safe to say that the accuracy is +- .0156 second, or more appropriately +- .016 second. +-1/64 second would also be appropriate.
1/64 is a 2-significant-figure quantity, so .016 is a good 2-significant-figure approximation.
However significant figures are by their nature only an approximate measure of precision. Percent error is more accurate.
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What is the shortest time interval you think you would be able to measure with reasonable accuracy?
answer/question/discussion: ->->->->->->->->->->->-> sion (start in the next line):
I think the shortest interval possible would be the .015625, however this doesn’t take into account the skill of the human clicking the mouse.
I really don’t know how to put a number on my mouse skills, other than to say I hope my life never depends on it. Or at least that my life never depends on consistent mouse skills.
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It would be challenging for a human-triggered timer to be very accurate with intervals much less than a second. With training some people might be capable of timing events separated by a quarter of a second, but I don't know of any studies and haven't conducted any myself.
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How does the percent error in timing intervals change as the time between the events gets smaller?
answer/question/discussion: ->->->->->->->->->->->-> sion (start in the next line):
The percent error increases as the time between events gets smaller. The percent error is equal to the error/actual measurement times 100%. If the number in the denominator gets smaller the answer will get larger. When you decrease the denominator, your answer increases.
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How accurately are you able to measure the positions of the ball and the pendulum in the initial video?
answer/question/discussion: ->->->->->->->->->->->-> sion (start in the next line):
I would say that accuracy can be measured to +/- 1 inch. Although the ruler has fractions of an inch, it is not possible to see them in the video. The only clearly visible gradations are the inches.
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15 minutes
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&#Good work. See my notes and let me know if you have questions. &#
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This is a resubmission / double submission. I submitted this just now on a Submit Work Form rather than this specific form.
I apologize for the inconvenience.