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course PHY-242
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 's expectations.
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
As I have seen and indicated in the timer lab, the computer is accurate only to 0.15 seconds, meaning that hundreds places are probably not accurate estimation with the Timer Program
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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
I think that the Keyboard and Mouse also act on a similar synchronization interval, that the computer will record the same time interval if I click within .01 milisecond earlier or later. Time passes from the instance I see something, to the instances that my brain processes the information, to the instance that my brain sends a signal to the arm, to the instance that my arm actually clicks, to the interval that the mouse sends off the signal.
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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
As the moon travels around the earth, water rises and falls in the oceans. Doing the experiment in the morning, will yield one result. After eating lunch and doing the same experiment, will yield a slightly different result compared to the new location of the moon.
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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 object is placed higher in the elevation, it will reach higher speed and father distance. If the object is placed lower in the elevation, it will reach lower speed and shorter distance.
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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
If the person performs the experiment late in the evening, he will be more tired, will have slower reaction and will most likely slower respond to recording the exact moment of the object reaching the end of the incline. If the person performs the experiment in the morning, he will be more energetic, will have faster reaction and will most likely quicker respond to recording the exact moment of the object reaching the end of 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: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
The more the experiment is repeated, the more accurately the timer program will show the time
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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
The more the experiment is repeated, the more a human will train himself to quickly and accurately click the mouse
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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
Read my previous response about the moon and its gravity effect
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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: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
The more height are tried out, the more pattern a person will see of height verses speed, or height versus distance traveled
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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: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
The more a person does something, the more better he becomes at doing the job and the more accurately he learns to perform the job. Therefore, the more attempts, the more accurately the person will be able to observe the exactly location, when the object reached the incline.
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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
Java language runs slowly, while C language runs quickly and Assembly language runs quickest. Write the program in C or assembly language to increase the certainty of the program.
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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:
Record a video of human triggering. After the video is recorded, count how many milliseconds passed from the actual event occurring, to the human clicking the mouse and for the result to appear on the screen. Rely not on the actual timing by hand, but on the recorded video, where you can count the event one frame at a time.
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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
Same answer as one above. Record the video of the event. Rely not on the actual timing by hand, but on the recorded video, where you can count the event to the precision of one frame at a time.
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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: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
Use very accurate ruler with millimeter marks to position the exact height. Maker sure the table is straight and not crooked.
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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: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
Record the event. Rely not on the actual timing by hand, but on the recorded video, where you can count the event one frame at a time.
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&#Your work looks good. Let me know if you have any questions. &#