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course Phy 232
6/3/12 due by 6/3/12 submitted around 6:26 PM
ph2 query 0Most queries in this course will ask you questions about class notes, readings, text problems and experiments. Since the first two assignments have been lab-related, the first two queries are related to the those exercises. 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.
Different first-semester courses address 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 instructor with your work and you with the instructor 'sexpectations.
Comment on your experience with the three lab exercises you encountered in this assignment or in recent assignments.
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Question: 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 a steel 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:
• The lack of precision of the TIMER program.
To what extent to you think the discrepancies are explained by this factor?
your answer: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
The TIMER program is dependent on the computer capability to accurately capture the times you need. The TIMER program is at least accurate to the .01 place, which would be more accurate than if a human was timing it.
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• The uncertain precision of human triggering (uncertainty associated with an actual human finger on a computer mouse)
To what extent to you think the discrepancies are explained by this factor?
your answer: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
The discrepancies of this factor are very high. It is very hard to accurately click at the right time during the experiment; your eye hand coordination would have to be extraordinary to hit the mouse at the exact time you want, this usually does not happen. Also this leaves more room to inaccurately take a time.
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• Actual differences in the time required for the object to travel the same distance.
To what extent to you think the discrepancies are explained by this factor?
your answer: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
The actual time required for the object to travel a distance could be altered if there is any external force acting on the steel ball such as friction or air distance.
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• Differences in positioning the object prior to release.
To what extent to you think the discrepancies are explained by this factor?
your answer: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
If the positioning of the object is different each time then your data could be off each time since you are not keeping each run the same. For example, I you start the ball at the same place each time the data will be more consistent but if you start the ball at different places then you will create a more random data that will have no accuracy or precision.
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• Human uncertainty in observing exactly when the object reached the end of the incline.
To what extent to you think the discrepancies are explained by this factor?
your answer: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
The problem of human uncertainty in observing exactly when the object reached the end of the incline is that if there are different people observing this experiment then they will get different answers based on when they clicked the timer. For example, if a person measures consistently at one time then their data will differ from another person who has measured using their end point on the incline.
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Question: 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?
• The lack of precision of the TIMER program.
To what extent to you think this factor would contribute to the uncertainty?
Your answer:
The TIMER program would not contribute that much to the uncertainty to the ball-down-an-incline lab, since it has very high accuracy.
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• The uncertain precision of human triggering (uncertainty associated with an actual human finger on a computer mouse)
To what extent to you think this factor would contribute to the uncertainty?
your answer: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
This factor would contribute to a lot of the uncertainty in the ball-down-an-incline lab, since this depends on how much time it took a student to see and then register the thought to click to record the data.
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• Actual differences in the time required for the object to travel the same distance.
To what extent to you think this factor would contribute to the uncertainty?
your answer: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
The actual differences in the time required for the object to travel the same distance would create a small amount of uncertainty. If a person pushed the ball instead of just letting it go then this would create a faster time and the ball would have force acting on it this could create less accuracy of the timing. Yet, most experience people would not contribute to this uncertainty.
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• Differences in positioning the object prior to release.
To what extent to you think this factor would contribute to the uncertainty?
Your answer:
The differences in positioning the object prior to release would contribute a small amount of uncertainty, since most people can accurately place the ball consistently in the same spot most of the time the position my only vary by a millimeter or so.
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• Human uncertainty in observing exactly when the object reached the end of the incline.
To what extent to you think this factor would contribute to the uncertainty?
Your answer:
The human uncertainty in observing exactly when the object reached the end of the incline could contribute a medium amount of uncertainty. If a person is not experience in taking data measurements then they could be a little off in their data.
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Question: What, if anything, could you do about the uncertainty due to each of the following? Address each specifically.
• The lack of precision of the TIMER program.
What do you think you could do about the uncertainty due to this factor?
your answer: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
There is not much you can do about the lack of precision of the TIMER program since that is the limitation of the program itself.
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• The uncertain precision of human triggering (uncertainty associated with an actual human finger on a computer mouse)
What do you think you could do about the uncertainty due to this factor?
your answer: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
For this factor you could take data several times to get the feel for when you should click, this would help with the hand eye coordination.
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• Actual differences in the time required for the object to travel the same distance.
What do you think you could do about the uncertainty due to this factor?
your answer: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
This uncertainty can be fixed by making sure that you do not put any external force on the ball when you release it.
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• Differences in positioning the object prior to release.
What do you think you could do about the uncertainty due to this factor?
Your answer:
This uncertainty can be fixed by either measuring or marking where you are placing the ball prior to release. This will make it easier to accurately place the ball each time.
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• Human uncertainty in observing exactly when the object reached the end of the incline.
What do you think you could do about the uncertainty due to this factor?
Your answer:
This uncertainty can be fixed by practicing a couple times before you actually take you data to get a feeling where the end of the incline is.
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&#Your work looks very good. Let me know if you have any questions. &#