course Phy 202 ߐú簖܊lyȮ^passignment #000
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19:04:19 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 --> I readily understood the concepts presented in the intial experiments. The experiments asked me to use different programs and learn different formulas which will be helpful in the course. However, they took me longer than they probably should have. As well I had several technical difficulties which were not a function of the course but of my own computer.
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19:13:39 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 only measures to the hundredths so that limits is precision because you must allow a certain level of uncertainty in the last place of the measurement. b. There is a natural delay between the eye seeing an occurance, the brain understanding and then triggering an action in response. As well there is also human error in carelessness etc. c. Differences can occur to many things such as if the object is on a slope. As the incline increase, the distance remains the same, but the speed will increase. Also if the release changes-if the object is merely released or pushed changes things. d. As previously mentioned if the height at which the object is released from increases the speed increases and vice versa. e. Again it can be due to simply the fact that angle of view may change the perception of when it gets to the end of the incline, the fact that there is a delay in between the occurance and realizing the occurance has happened, and human error. confidence assessment: 2
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19:21:16 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. I do not think it is the largest contributing factor though does contribute and should not be ignored. b. I think this is a much larger factor in the uncertainty; probably the greatest in my opinion atleast in my case. Incomplete clicks etc. c. I think it is minor as long as the set up is the same each time and the release is the same. d. I think this too a large contributor to differences because different inclines or positions along an incline will increase or decrease the rate at which it travels. e. I think human uncertainty in observation can be a major contributor to the overall uncertainty if the observer is not extremely careful and if the vantage point does not provide a clear view. confidence assessment: 2
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19:24:59 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. There is nothing you can do; unless you create a new program. b. Practice with the mouse beforehand, make sure your equipment works consistently, and finally be as careful as possible. c. There is nothing you can do but make sure the experiment runs as consistently as possible. d. Keep the experiment completely consistent. Clearly mark the release position so it is repeatable. e. Have a clear view of the end of the incline and pay attention! Also having more than 1 person watching and timing would decrease the uncertainty. confidence assessment: 2
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