asst 0 query

course phy 201

¦Øù™Úº¡ ÈäâF¿ÊÀ»LË\à|ÔxÑN°™©n­•†assignment #000

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000. `Query 0

Physics I

01-23-2007

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14:55:43

The Query program normally asks you questions about assigned problems and class notes, in question-answer-self-critique format. Since Assignments 0 and 1 consist mostly of lab-related activities, most of the questions on these queries will be related to your labs and will be in open-ended in form, without given solutions, and will not require self-critique.

The purpose of this Query is to gauge your understanding of some basic ideas about motion and timing, and some procedures to be used throughout the course in analyzing our observations. Answer these questions to the best of your ability. If you encounter difficulties, the instructor's response to this first Query will be designed to help you clarify anything you don't understand. {}{}Respond by stating the purpose of this first Query, as you currently understand it.

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RESPONSE -->

ok

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14:56:36

If, as in the object-down-an-incline experiment, you know the distance an object rolls down an incline and the time required, explain how you will use this information to find the object 's average speed on the incline.

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RESPONSE -->

distance divided by time = speed

confidence assessment: 3

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15:01:57

If an object travels 40 centimeters down an incline in 5 seconds then what is its average velocity on the incline? Explain how your answer is connected to your experience.

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RESPONSE -->

40/5=8centimeters per second

this is connected to the experiment because we had to find the speed at which the oblect rolled down our book.

confidence assessment: 3

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15:06:06

If the same object requires 3 second to reach the halfway point, what is its average velocity on the first half of the incline and what is its average velocity on the second half?

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RESPONSE -->

first half

20/3=6.67 cm per sec. average speed

second half

20/2=10 cm per sec. average speed

confidence assessment: 3

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15:07:40

Using the same type of setup you used for the first object-down-an-incline lab, if the computer timer indicates that on five trials the times of an object down an incline are 2.42 sec, 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 thefollowing: {}{}a. The lack of precision of the TIMER program{}{}b. The uncertain precision of human triggering (uncertainty associated with an actual human finger on a computer mouse){}{}c. Actual differences in the time required for the object to travel the same distance.{}{}d. Differences in positioningthe object prior to release.{}{}e. Human uncertainty in observing exactly when the object reached the end of the incline.

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RESPONSE -->

B and E

confidence assessment: 3

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15:16:14

How much uncertainty do you think each of the following would actually contribute to the uncertainty in timing a number of trials for the object-down-an-incline lab? {}{}a. The lack of precision of the TIMER program{}{}b. The uncertain precision of human triggering (uncertainty associated bLine$(lineCount) =with an actual human finger on a computer mouse){}{}c. Actual differences in the time required for the object to travel the same distance.{}{}d. Differences in positioning the object prior to release.{}{}e. Human uncertainty in observing exactly when the object reached the end of the incline.

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RESPONSE -->

a. not much uncertainty

b.human interpretation is the biggest factor in uncertainty

c.there will be no difference in the ""actual"" time it takes.

d.unless you place a backboard up against the top of the incline it is hard to place it in the exact same spot every time.

e. this has a lot to do with the time differences

confidence assessment: 3

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15:21:02

What, if anything, could you do about the uncertainty due to each of the following? Address each specifically. {}{}a. The lack of precision of the TIMER program{}{}b. The uncertain precision of human triggering (uncertainty associated with an actual human finger on a computer mouse){}{}c. Actualdifferences in the time required for the object to travel the same distance.{}{}d. Differences in positioning the object prior to release.{}{}e. Human uncertainty in observing exactly when the object reached the end of the incline.

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RESPONSE -->

a not really anything

b.keep doing it over and over and try to get better

c.nothing, it doesn't change

d. put a backborad at the top of the incline or make a mark on the incline

e. there is really nothing we can do about human judgement but practicing and repetition would help.

confidence assessment: 3

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This looks good. Keep up the good work.