#$&*
course Phy 122
ph2 query 0Most queries in this course will ask you questions about class notes, readings, text problems and experiments. Since the first two assignments have been lab-related, the first two queries are related to the exercises. While the remaining queries in this course are in question-answer format, the first two will be in the form of open-ended questions. Interpret these questions and answer them as best you can. Different first-semester courses address the issues of experimental precision, experimental error, reporting of results and analysis in different ways and at different levels. One purpose of these initial lab exercises is to familiarize your instructor with your work and you with the instructors expectations. Comment on your experience with the three lab exercises you encountered in this assignment or in recent assignments.
Question: This question, related to the use of the TIMER program in an experimental situation, is posed in terms of a familiar first-semester system.
Suppose you use a computer timer to time a steel ball 1 inch in diameter rolling down a straight wooden incline about 50 cm long. If the computer timer indicates that on five trials the times of an object down an incline are 2.42sec, 2.56 sec, 2.38 sec, 2.47 sec and 2.31 sec, then to what extent do you think the discrepancies could be explained by each of the following:
The lack of precision of the TIMER program.
To what extent to you think the discrepancies are explained by this factor?
Your answer:
The timer could have been started at different times and stopped at different times. The computer could have also delayed the program from starting.
#$&*
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 person could hit the start button at different times and the reaction time could have been delayed.
#$&*
Actual differences in the time required for the object to travel the same distance.
To what extent to you think the discrepancies are explained by this factor?
your answer: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
The ball could move at different speeds for each trail which would delay the time.
#$&*
Differences in positioning the object prior to release.
To what extent to you think the discrepancies are explained by this factor?
Your answer:
The positioning could be placed at different positions on the ramp which would have a factor on the time.
#$&*
Human uncertainty in observing exactly when the object reached the end of the incline.
To what extent to you think the discrepancies are explained by this factor?
Your answer:
The person could react at different times when they think the object has reached the end of the incline.
#$&*
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
I think this would play a big role of uncertainty. But I think every discrepancy would play a role in the project because they all change the time for the project.
#$&*
The uncertain precision of human triggering (uncertainty associated with an actual human finger on a computer mouse)
To what extent to you think this factor would contribute to the uncertainty?
your answer: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
I dont think this is a big problem unless the reaction time is long before hitting the button to start the timer and the ball already half way down the incline.
#$&*
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
This should not be a big discrepancy as long as the numbers are close together and not far away.
#$&*
Differences in positioning the object prior to release.
To what extent to you think this factor would contribute to the uncertainty?
Your answer:
This would not be a big problem as long as the positions are close together and not a big distance between them.
#$&*
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:
This would not be a big deal as long as the human does not wait a long time until they hit the button to end the timer.
#$&*
Question: What, if anything, could you do about the uncertainty due to each of the following? Address each specifically.
The lack of precision of the TIMER program.
What do you think you could do about the uncertainty due to this factor?
your answer: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
Be more precise when hitting the start and end button to have a more valuable time.
#$&*
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
Make sure to limit the amount of reaction time during the project so the time would be correct.
#$&*
Actual differences in the time required for the object to travel the same distance.
What do you think you could do about the uncertainty due to this factor?
Your answer:
Try to hit the start and end button as soon as the ball is released and comes to the end.
#$&*
Differences in positioning the object prior to release.
What do you think you could do about the uncertainty due to this factor?
Your answer:
Try to position the ball in the same position each time you release the ball.
#$&*
Human uncertainty in observing exactly when the object reached the end of the incline.
What do you think you could do about the uncertainty due to this factor?
your answer: vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
Try to observe the object when it reaches the end of the incline and hit the button to stop the timer to have an accurate result.
#$&*
"
end document
&#This looks good. Let me know if you have any questions. &#