cq_1_012

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PHY 201

Your 'cq_1_01.2' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.

** CQ_1_01.2_labelMessages **

Samantha Rogers

PHY 201

Seed 1.2

The problem:

Answer the following:

• How accurately do you think you can measure the time between two events using the TIMER program? 

answer/question/discussion: ->->->->->->->->->->->-> (start in the next line): 

 I do not think that the TIMER program is very accurate, but when measuring between two events I think I can accurately measure the time. This is because the inaccuracy will be accurate between the two events.

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You can give a quantitative answer to this question. To exaggerate a little bit (actually a lot) you know that you can time to within an accuracy of +- 1 minute, and you should know that you can't time accurately to within the microsecond (one-millionth of a second).

So there's an upper limit of +- 1 minute, and a lower limit of +- 1 microsecond on the uncertainty in your measuremtn of the interval.

Obviously we can bring those limits closer. For example, we could certainly time within +- 1 second. Our reactions aren't consistent enough to time within +- 100 milliseconds (that's 1/10000 second), so we can place upper and lower limits of +- 1 second, and +-.0001 second on our accuracy.

What are the best upper and lower limits you would be comfortable asserting for this process?

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• What is the shortest time interval you think you would be able to measure with reasonable accuracy? 

answer/question/discussion: ->->->->->->->->->->->-> (start in the next line): 

 The shortest time interval I think that I would be able to measure with reasonable accuracy would be around 1 second (this is after taking in all of the discrepancies).

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• How does the percent error in timing intervals change as the time between the events gets smaller? 

answer/question/discussion: ->->->->->->->->->->->-> (start in the next line): 

 As the time between the events gets smaller the percent error in timing intervals gets larger. When the time between the events gets smaller it makes it harder to time exactly, making the percent error greater.

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• How accurately are you able to measure the positions of the ball and the pendulum in the initial video?

answer/question/discussion: ->->->->->->->->->->->-> (start in the next line): 

 I think that I was able to measure the positions of the ball and pendulum in the initial video pretty accurately but I do believe that i made errors as well because the video was not completely clear.

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A quantitative answer is also possible here. Certainly you could measure positions to within a foot, and clearly you could not measure positions to within a millimeter.

What limits would you put on the possible degree of precision?

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Good. Do submit a revision, though, which answers the two questions I posed.

&#Please see my notes and submit a copy of this document with revisions, comments and/or questions, and mark your insertions with &&&& (please mark each insertion at the beginning and at the end).

Be sure to include the entire document, including my notes.

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