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course Phy 231
6/4/12 @ 4:50pm
timer program#$&*
Phy 231
Your 'timer program' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** TIMER program_labelMessages **
6/1/12 @ 11:19am
** **
30 minutes
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It is easy to operate the Timer program. All you have to do is click on the button labeled Click to Time Event.
Click that button about 10 times and describe what you see.
It shows a chart of 1-10 with two columns of different numbers. In the top left hand corner ths click to time event button is there then on the right side it shows 10 and the first number in the column for #10.
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Now click on Initialize Counter, which will clear all the data from the timer window. Click the mouse as fast as you can until the TIMER window fills up. Be sure you get at least 20 time intervals.
If you miss a click, try again. Keep trying until you get at least 20 intervals without a missed or delayed click.
Copy your data starting in the next line:
1 0 0
2 .15625 .15625
3 .25 .09375
4 .359375 .109375
5 .4648438 .1054688
6 .5742188 .109375
7 .7929688 .21875
8 .9179688 .125
9 1.027344 .109375
10 1.152344 .125
11 1.261719 .109375
12 1.355469 .09375
13 1.605469 .25
14 1.730469 .125
15 1.855469 .125
16 2.105469 .25
17 2.230469 .125
18 2.339844 .109375
19 2.480469 .140625
20 2.589844 .109375
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Your data are a bit flawed. You had intervals of .22 and .25 seconds, which pretty clearly given your (quite fast) clicking speed correspond to missed clicks.
It takes only seconds to get a set of data, and good lab procedure at this point would be to repeat the process until you have a valid set of data.
No need to redo anything, but be sure you understand the general principle that data need to correspond to the quantity being measured.
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You got at least 20 time intervals. Based on your data what was the average of the first 20 time intervals? Note that you could get this average by averaging the first 20 intervals. My first few intervals were .15625, .15625, .1875, .171875, etc; I could just add up the first 20 intervals and divide by 20 to get the average. However there is an easier and quicker way to get the result, so use the easier way if you can.
Give your result, number only, in the first line, and starting in the second line explain how you got it.
1.26 is the average
I got it by simply adding up all of the numbers in the first column and I then divided by 20.
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Your quick-click intervals were all in the vicinity of 0.1 second. All the intervals you reported were much less than 1.26 seconds. So 1.26 seconds cannot be the mean interval.
&&& I meant to but .129 for my average&&&
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When I did this activity the first few lines of my data were as follows:
event number clock time time interval
1 11.67188 11.67188
2 11.875 0.203125
3 12.0625 0.1875
4 12.20313 0.140625
5 12.375 0.171875
6 12.54688 0.171875
7 12.73438 0.1875
8 12.92188 0.1875
9 13.10938 0.1875
10 13.28125 0.171875
11 13.4375 0.15625
It looks like the same intervals keep popping up. For example .1875 seconds occurs 5 times out of the first 10 intervals, .171875 seconds occurs three times, and .203125 seconds, .140625 seconds and .15625 seconds each occur once.
A frequency distribution for my time intervals would be as follows:
time interval frequency
,140625 1
.15625 1
.171875 3
.1875 5
.203125 1
What different time intervals did you observe in your first 20 intervals, and how many times did each occur? List below the different time intervals you observed and the number of times each occurred. List from the shortest to the longest interval, and use a comma between the time interval and its frequency. For example my data above would be listed at
.140625, 1
.1565, 1
.171875, 3
.1875, 5
.203125, 1
Your list should be in exactly this format, with no other symbols or characters.
.09375, 2
.109375, 6
.125, 5
.25, 2
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You may make any comments or ask any question about the process so far in the box below
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On the 10 intervals I've shown you, do you really think I managed to get a time of .1875 seconds, accurate to 4 significant figures, on half of the intervals? If you do, I'm grateful for your confidence but I'm just not that good. No human being has that much neurological and muscular control.
So why do you think the TIMER program reported that time so frequently? Why weren't there times like .1830 seconds, or .1769 seconds? Does this mean that the TIMER program is flawed? Does that mean it's useless?
I think that its just how the program is designed. There may be a flaw? But I am not sure.
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Here are a few more lines of data, with an added column showing the difference between each time interval and the next.
clock time time interval difference from one time interval to next
9 13.10938 0.1875 -0.01563
10 13.28125 0.171875 -0.01563
11 13.4375 0.15625 0.03125
12 13.625 0.1875 -0.01563
13 13.79688 0.171875 0.015625
14 13.98438 0.1875 0.015625
15 14.1875 0.203125 -0.03125
16 14.35938 0.171875 -0.01563
17 14.51563 0.15625 0.03125
Take a good look at that last column and tell us what you see in those numbers, and what this tells you about the TIMER program
I can see that the TIMER program may not be 100% accurate.
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Now initialize the TIMER once more, and take a series of 10 relaxed breaths. Every time you start to inhale, hit the TIMER button.
My results for the first 7 complete breaths are as follows:
series of relaxed breaths
event number clock time time interval difference between time interval and next
1 1569.734 1569.734
2 1582.75 13.01563 0.32812
3 1596.094 13.34375 3.90625
4 1613.344 17.25 2.70313
5 1633.297 19.95313 1.35937
6 1654.609 21.3125 4.23438
7 1680.156 25.54688 2.15625
8 1707.859 27.70313
I didn't go on because the time between my breaths kept increasing, and I was afraid if I relaxed any more I might stop breathing altogether. It's going to take either more statistical analysis to determine whether that's a real danger, or a little common sense.
Report your results by just entering your time intervals, one to each line, in the box below. If I was entering my results I would enter
13.01563
13.34375
17.25
19.95313
21.3125
etc.
Enter your results in the same format:
2.855469
7.375
9.660156
12.94141
17.66016
21.9375
26.89453
31.63672
37.18359
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If you have any comments please insert them here
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Most likely you did not observe the same exact time interval twice, and if you did it did not happen nearly as often as when you did the fact clicks.
Why do you think this is exactly what we would expect?
Im not really sure.
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Which of the following statements do you think is the most accurate?
a. The TIMER program is capable of determining the time between two events accurately to within about .1 second.
b. The TIMER program is capable of determining the time between two events accurately to within about .01 second.
c. The TIMER program is capable of determining the time between two events accurately to within about .001 second.
d. The TIMER program is capable of determining the time between two events accurately to within about .0001 second.
Enter your answer and your reasoning below:
d. The TIMER program is capable of determining the time between two events accurately to within about .0001 second.
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If the TIMER was accurate to .0001 second, then what would be the chances that several of your clicks would have ended up with exactly the same interval, and that indeed only four or five different intervals occurred on 20 observations?
&&&& So would the correct answer be A. .1 seconds???&&&
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*#&!
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See my notes and please revise by recalculating the mean time interval, and further addressing that last question.
You don't need to take new data.
&#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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&#This looks good. Let me know if you have any questions. &#