#$&*
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 **
I could not figure out how to Save the timer, I wanted to have it on my desktop.
** **
an hour and a half
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DO NOT COPY THE LINES ABOVE THIS ONE. JUST FILL THOSE LINES IN WHEN YOU SUBMIT YOUR RESULTS AT THE END OF THIS FORM.
Follow the instructions, fill in your data and the results of your analysis in the given format.
Regularly save your document to your computer as you work.
When you have completed your work:
Highlight the contents of the text editor, and copy and paste those contents into the indicated box at the end of this
form.
Click the Submit button and save your form confirmation.
This experiment is self-explanatory. Student report time of completion ranging from 10 minutes to 1 hour, with 30 minutes
being the most typical.
Downloading and/or running the TIMER program
If you have a Macintosh computer the preferred timer.exe program might not work (it will if your computer has a Windows
emulator), but the alternative Java applet should work just fine.
timer.exe
The program timer.exe should be downloaded to your hard drive and/or flash drive so you have access to it whenever you need
it.
There is an alternative Java applet (see the heading timer java applet below) , but the .exe option is preferable. It is
worth 15 minutes of effort to get the program working on your hard drive, after which you will have it and won't need
Internet access to run it. It will start up instantly, it runs in a small window, and it has the ability to file your
data. However if you can't get it working in 15 minutes with the instructions given below, just move on the the Java
version.
To use the Windows version:
If you are using a Windows PC, or a Mac with Windows emulator, first take a few seconds to run the program q a prelim. As
soon as the form opens on your screen, you can close it. Nothing needs to be submitted. The first thing this program does
is to create the c:\vhmthphy folder on your hard drive. As an alternative you can also create a c:\vhmthphy folder.
The timer.exe program opens in a small window and can be run side-by-side with other windows applications on your computer
(just size the second window so it leaves room for the Timer program).
Run the program now. If it fails to work then try the following, in order:
If you got the Run-time Error 76, it can be corrected by the step given earlier. That instruction is repeated below:
Run the program q a prelim. As soon as the form opens on your screen, you can close it. Nothing needs to be submitted.
The first thing this program does is to create the c:\vhmthphy folder on your hard drive. As an alternative you can
manually create this folder.
If this doesn't work, follow the link COMDLG32 to access simple instructions for fixing the problem. Then run timer.exe .
To use the Java version:
Windows users:
The Java applet does require that the Java Runtime Environment be installed. Almost every Apple computer, and most Windows
computers, will have this environment installed. If your computer will not run the Java applet, the installation is simple
and quick. If you search under 'Java Runtime Environment', using any search engine, you will find information on the Java
Runtime Environment and on the installation. You should satisfy yourself that you are downloading from a verifiable,
trusted source.
Mac users:
Apple supplies their own version of Java. Use the Software Update feature (available on the Apple menu) to check that you
have the most up-to-date version of Java for your Mac.
should check the Apple site for the Software Update feature (available on the Apple menu) to check that you have the most
up-to-date version of Java for your Mac.
The Java Applet at the link Timer-Java will work fine for the current experiment, and will do just about everything the
timer.exe program will do. The Java applet has a few more or less minor inconveniences and one that's not quite as minor:
You can't put the Java applet on your hard drive or flash drive, so you have to pull it off the Web every time you want to
use it.
The applet won't file your data. However it will let you copy and paste your data into a text editor.
If your machine doesn't run Java applets, you would have to set it up to do so (just search the web under 'Java Runtime
Environment', which is free and installs easily). This software is pretty standard, and is already installed on most
machines.
Operating the TIMER program
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.
I see it start on 1,40.42118, 402118. It counts up with each click, with first column showing the click number, second
column is the next count, and the final column is the difference between the present and past clicks in seconds.
#$&*
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 quick-click intervals without a missed or delayed
click.
Copy your data starting in the next line:
1 398.4023 398.4023
2 398.5938 .1914063
3 398.6953 .1015625
4 398.793 9.765625E-02
5 398.9023 .109375
6 399 9.765625E-02
7 399.1016 .1015625
8 399.1992 9.765625E-02
9 399.2969 9.765625E-02
10 399.4023 .1054688
11 399.4961 .09375
12 399.6055 .109375
13 399.707 .1015625
14 399.8164 .109375
15 399.918 .1015625
16 400.0234 .1054688
17 400.125 .1015625
18 400.2305 .1054688
19 400.3359 .1054688
20 400.4414 .1054688
21 400.5469 .1054688
22 400.6406 .09375
#$&*
You got at least 20 time intervals. Based on your data what was the average of the first 20 time intervals? Note that you
could get this average by averaging the first 20 intervals. My first few intervals were .15625, .15625, .1875, .171875,
etc; I could just add up the first 20 intervals and divide by 20 to get the average. However there is an easier and
quicker way to get the result, so use the easier way if you can. NOTE: Spreadsheet calculations and other methods that
disguise the process of finding the average are not valid answers to this question. Spreadsheets are perfectly legal for
most data analysis, but not in this experiment.
Give your result, number only, in the first line, and starting in the second line explain how you got it.
average of quick-click intervals:
.1054688
explanation:
It is the number that is repeated the most, or has the most frequency in the amount of clicks.
#$&*
@&
The median or the mean would be more appropriate to this data set, but the mode is a valid average.
*@
@&
The median or the mean would be more appropriate to this data set, but the mode is a valid average.
I suspect that the median would coincide with the mode.
The mean would be skewed a bit by the .19 second interval, which probably represents a missed click.
Those are fast times, incidentally. Not quite below the .10 second level, but an average below .10 second is rare. I've seen it only a few times in over a decade.
*@
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
The above list is called a frequency distribution. Be sure you make note of this terminology.
Your list should be in exactly the above format, with no other symbols or characters.
Your list (i.e., your frequency distribution):
9.765625E-02, 3
.09375, 2
.1015625, 5
.1054688,6
.109375, 1
.1914063, 1
#$&*
You are welcome make any comments or ask any question about the process so far.
#$&*
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?
Why did the TIMER report .1875 seconds multiple times; your conclusions about the program:
It did so by calculating the correct number of significant figures when in compared and subtracted from two different
times, with two different numbers of figures. It took the awnser and rounded it off to the number with the least amount of
significant figures.
#$&*
Here are a few more lines of data, with an added column showing the difference between each time interval and the next.
clock time time interval difference from one time interval to next
9 13.10938 0.1875 -0.01563
10 13.28125 0.171875 -0.01563
11 13.4375 0.15625 0.03125
12 13.625 0.1875 -0.01563
13 13.79688 0.171875 0.015625
14 13.98438 0.1875 0.015625
15 14.1875 0.203125 -0.03125
16 14.35938 0.171875 -0.01563
17 14.51563 0.15625 0.03125
Take a good look at that last column and tell us what you see in those numbers, and what this tells you about the TIMER
program:
In the last column i see that the differences are really small and that the number of figures used are dependent on the two
numbers that proceed and follow it. The timer program finds the difference in between two numbers and siplays it correct to
the least amount of significant digits.
#$&*
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:
4.84375
5.667969
8.105469
6.324219
5.363281
6.988281
6.722656
7.152344
7.214844
#$&*
If you have any comments please insert them here
#$&*
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?
Since the intervals between clicks is alot longer, the differences between them will be greater, and the frequency of
having the same amount of time pass in between them will go down significantly.
#$&*
Which of the following statements do you think is the most accurate?
a. The TIMER program is capable of determining the time between two events accurately to within about .1 second.
b. The TIMER program is capable of determining the time between two events accurately to within about .01 second.
c. The TIMER program is capable of determining the time between two events accurately to within about .001 second.
d. The TIMER program is capable of determining the time between two events accurately to within about .0001 second.
Enter your answer and your reasoning below:
d.
This was the lowest amount of digits i have seen thus far, so If i were taking mesurements of a system, and this was the
least amount of digits I seen, I would base the accuracy of my entire results to this number of seconds.
@&
Just because the program displays those digits doesn't make them significant.
I the digits down to .0001 were significant, it would have been unlikely that any of the intervals would have repeated. Since most of the intervals you observed were repeated, some as many as 5 or 6 times, it's extremely improbable that time intervals were determined to that many significant figures.
*@
#$&*
&#Good responses on this lab exercise. See my notes and let me know if you have questions.
Revision isn't requested, but if you do choose to submit revisions, clarifications or questions, please insert them into a copy of this document, 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. &#