course Phy 202 ëñ•ŸáÁ®ÝNùéÔ¨MÆÆûÑÃñÆassignment #000
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18:04:37 Most queries in this course will ask you questions about class notes, readings, text problems and experiments. Since the first two assignments have been experiments, the first two queries are related to the experiments. While the remaining queries in this course are in question-answer format, the first two will be in the form of open-ended questions. Interpret these questions and answer them as best you can.
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RESPONSE --> OK
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18:06:05 Different first-semester courses addressed the issues of experimental precision, experimental error, reporting of results and analysis in different ways and at different levels. One purpose of these initial lab exercises is to familiarize your instuctor with your work and you withthe instructor 's expectations. {}{}Comment on your experience with the three lab exercises you encountered in this assignment.
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RESPONSE --> These assignments and labs have helped me prepare myself for this course by helping me run tests, collect data, and report my observations
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18:17:54 This question, related to the use of the TIMER program in an experimental situation, is posed in terms of a familiar first-semester system. Suppose you use a computer timer to time asteel ball 1 inch in diameter rolling down a straight wooden incline about 50 cm long. If the computer timer indicates that on five trials the times of an object down an incline are 2.42sec, 2.56 sec, 2.38 sec, 2.47 sec and 2.31 sec, then to what extent do you think the discrepancies could be explained by each of the following: {}{}a. The lack of precision of the TIMER program{}{}b. The uncertain precision of human triggering (uncertainty associated with an actual human finger on a computer mouse){}{}c. Actual differences in the time required for the object to travel the same distance.{}{}d. Differences in positioning the object prior to release.{}{}e. Human uncertainty in observing exactly when the object reached the end of the incline.
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RESPONSE --> a. The TIMER program had a glitch and was showing a time slower or faster than when the human clicked the mouse. b. The person doing the clicking was not very good at clicking the mouse when the ball finished its roll down the 50cm. wood ramp. c. The ramp was set a different angle on a few of the runs. d. The ball was placed farther up or farther down the ramp showign the differences in the times. e. The human was clicking the mouse at different points and not a specific point of when the ball leaves the ramp. confidence assessment: 3
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18:18:11 How much uncertainty do you think each of the following would actually contribute to the uncertainty in timing a number of trials for the ball-down-an-incline lab? {}{}a. The lack ofprecision of the TIMER program{}{}b. The uncertain precision of human triggering (uncertainty associated with an actual human finger on a computer mouse){}{}c. Actual differencesin the time required for the object to travel the same distance.{}{}d. Differences in positioning the object prior to release.{}{}e. Human uncertainty in observing exactly when the object reached the end of the incline.
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RESPONSE --> a. This uncertainty would be very significant in determining the timing of the trials. b. This is another area of the testing where the uncertainty would contribute a significant amount of difference between the times. c. An uncertainty with the actual differences in the time would cause a lot of uncertainty regarding the significantly different times for the same size ball rolling down the same length. d. I beleive this would cause the most uncertainty becuase the human would not know where each trial started causing him or her to be very uncertain of the actual timing. e. This is very important in determining the timing, so an uncertainty regarding the ball leaving the ramp would cause a major confusion of the timing. confidence assessment: 3
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18:22:26 What, if anything, could you do about the uncertainty due to each of the following? Address each specifically. {}{}a. The lack of precision of the TIMER program{}{}b. The uncertainprecision of human triggering (uncertainty associated with an actual human finger on a computer mouse){}{}c. Actual differences in the time required for the object to travel the same distance.{}{}d. Differences in positioning the object prior to release.{}{}e. Humanuncertainty in observing exactly when the object reached the end of the incline.
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RESPONSE --> a. Run different test using the timer compared to a stopwatch or another timer. b. Have another person do click the mouse for the trials of the ball rolling down the ramp and see how their results differ from the original human. c. Double check the ramp angle before each run to insure each run is traveling down the same slope. d. Have a mark on you wood ramp to show where to place the ball so each distance down the ramp will be the same. e. Have another human run the test and compare theirs with the orignial humans restults to see if there is a difference. confidence assessment: 3
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