ph2 query 0

Most 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.

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 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: 

#$&*

·          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: 

#$&*

·          Differences in positioning the object prior to release.

To what extent to you think the discrepancies are explained by this factor?

Your answer: 

#$&*

·          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: 

#$&*

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 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: 

#$&*

·          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: 

#$&*

·          Differences in positioning the object prior to release.

To what extent to you think this factor would contribute to the uncertainty?

Your answer: 

#$&*

·          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: 

#$&*

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: 

#$&*

·          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: 

#$&*

·          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: 

#$&*

·          Differences in positioning the object prior to release.

What do you think you could do about the uncertainty due to this factor?

Your answer: 

#$&*

·          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: 

#$&*