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PHY 202
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 **
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50 minutes
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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.
If the Timer-Java program won't run on your computer you might need to set Java to give it the necessary permissions. The instructions for doing so are as follows:
1. navigate to the java control panel by searching java from the windows search (start button on win 7) (move cursor to upper right corner to display search icon on win 8)
2. select configure
3. go to the security tab on the control panel.
4. select the edit site list option
5. select add and copy/paste the url of the page
6. apply settings
If these programs don't work there is a program at
• http://tools.arantius.com/stopwatch
that provides similar output. However the format of the output has its disadvantages, one being that the output is given in hour-minutes-seconds, a format that isn't compatible with, say, many spreadsheets. This would add significant editing time to some activities.
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.
The left-most column labels each time period (1-10, in this case), the middle column lists total time elapsed, and the right column lists the time difference between the current time and the preceding time. For example:
1 1.53125 1.53125
2 3.640625 2.109375
3 6.039063 2.398438
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Now click on Initialize or Reset the 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:
1 252.9063 252.9063
2 253.0625 .15625
3 253.1875 .125
4 253.3438 .15625
5 253.4453 .1015625
6 253.5938 .1484375
7 253.7109 .1171875
8 253.8359 .125
9 253.9766 .140625
10 254.1172 .140625
11 254.2422 .125
12 254.3672 .125
13 254.5078 .140625
14 254.6484 .140625
15 254.7734 .125
16 254.9297 .15625
17 255.0703 .140625
18 255.2109 .140625
19 255.3672 .15625
20 255.4922 .125
21 255.6328 .140625
22 255.7891 .15625
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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. 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: 0.130580357
explanation: I took the long way and averaged them with a calculator. I omitted the first row because it was timing the time it took for me to finish “initialize counter” and then commence clicking.
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That works, and your mean looks good.
Note that you could have subtracted the apporopriate clock times and divided by 20.
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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
(The Online Stopwatch program gives output that looks like the following:
Lap # This Lap Running Total
1 00:00:00.231 00:00:00.231
2 00:00:00.200 00:00:00.431
3 00:00:00.200 00:00:00.631
4 00:00:00.177 00:00:00.808
5 00:00:00.184 00:00:00.992
When copied into Notepad it comes out looking like this:
Lap # This Lap Running Total
1 00:00:00.231 00:00:00.231
2 00:00:00.200 00:00:00.431
3 00:00:00.200 00:00:00.631
4 00:00:00.177 00:00:00.808
5 00:00:00.184 00:00:00.992
6 00:00:00.241 00:00:01.233
16 00:00:00.178 00:00:03.327
If you search and replace 00:00: with four spaces you get
Lap # This Lap Running Total
1 00.231 00.231
2 00.200 00.431
3 00.200 00.631
4 00.177 00.808
5 00.184 00.992
6 00.241 01.233
which is usable.)
With my data, 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. With the Online Stopwatch program, we find that 0.200 seconds gets repeated once in 6 intervals.
A frequency distribution for my original 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):
0.1015625, 1
0.1171875, 1
0.125, 6
0.140625, 7
0.1484375, 1
0.15625, 5
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You are welcome make any comments or ask any question about the process so far.
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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?
Why did the TIMER report .1875 seconds multiple times; your conclusions about the program:
The TIMER probably does not roll through each ten-thousandth of a second (this would require great accuracy and most likely a larger file size) but rather probably estimates the closest possible time by reporting a set time (ie: 0.1875) when the event occurs between two known time intervals. For example, rather than being that accurate, the program has a number of known times and gives a near-approximation of the event’s occurrence to one of those known times.
I hope that makes sense because it does in my head!
This “limitation” of this program does not make it useless or flawed - it is simply limited, as are all scientific tools.
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Very good.
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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:
The last column shows the time difference between the current time interval to the next, meaning that the negative numbers show how much more quickly that event occurred than the next. For example, the time interval in #10 is shorter than the one in #9, which is further indicated by the negative number in the last column for event #9. This means that event #10 occurred that much more quickly than #9 did. The TIMER program thus is constantly comparing time intervals (and thus speeds) in addition to simply tracking time.
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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:
422.2422
5.304688
5.289063
7.234375
5.882813
5.585938
6.351563
7
6.640625
7.367188
5.304688
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If you have any comments please insert them here
I found the time interval of exactly “7” to be rather amazing.
I also found it interesting how much more quickly my breaths came than yours. I guess I wasn’t that relaxed!
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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?
When the program is faced with rapid-fire events, it uses near-approximations to be able to keep up. When faced with slower events, it becomes more accurate. This seems to make sense when considering that machines and tools are always limited and that lag-time may be a factor.
The lack of repeated time intervals may also be due to the wider range in breath time than rapid-click time. The former, while relatively consistent, may vary in the smaller increments as breaths take a longer amount of time. The latter, rapid-fire clicking, happens so quickly that there is less room for variation.
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Which of the following statements do you think is the most accurate?
a. The TIMER program (or the Java TIMER or the Online Stopwatch -- specify which) is capable of determining the time between two events accurately to within about .1 second.
b. The TIMER program (or the Java TIMER or the Online Stopwatch -- specify which) is capable of determining the time between two events accurately to within about .01 second.
c. The TIMER program (or the Java TIMER or the Online Stopwatch -- specify which) is capable of determining the time between two events accurately to within about .001 second.
d. The TIMER program (or the Java TIMER or the Online Stopwatch -- specify which) 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 0.0001 second. It frequently reports times to six decimal places, so it seems likely that it would be accurate to at least the first four.
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If you don't have a spreadsheet you should be able to easily access a free spreadsheet in order to do this last step. If you don't have time right now you can do this part later, and submit just a copy of this question and your response, using the Question Form .
If you don't know what text editor comes with your device (for Windows this would be Notepad), you should simple search the Web under 'text editing for ****' where **** is your device.
Note that this course is not intended to be run from a handheld device. Screens are too small to clearly see the necessary amount of content. However if either version of the TIMER runs on your handheld device and that device allows you the necessary functionality, it's fine to use it.
Note that the TIMER.exe program can save your data in a format that can be read by a spreadsheet (the TIMER applet cannot do so). This will be very handy in the future, so take a minute and do the following:
If you are using the TIMER.exe program:
1. Click on the button at the lower right of the TIMER form, entitled Click to File Data.
2. A box will pop up allowing you to include an identifying message. You should generally choose to include such a message; for the data presently on your timer that might be 'series of regular breaths time at beginning of inhalation' or something similar. Type in whatever you think would serve as a good identifier for this data and OK that box.
3. A typical Save As window will appear. Decide where to save your data and what to call it, and proceed to save it. The program will save the file as a comma-delimited text file.
4. Open your spreadsheet program (typically Excel) and choose File > Open. Browse to the folder in which you just saved your data. Below the File Name line will be a File Type line; set this either to Text Files or All Files so your file will appear. Open it.
5. A series of windows will typically appear. In the first window make sure the file type chosen is Delimited, the proceed to the next window.
6. In the second window you will see a series of checkboxes; check the one entitled Comma, in order to select the comma-delimited file, then just click on Finish.
If you are using the TIMER applet you can't do Steps 1-3. In this case:
Copy the contents of the program to a text file, using copy-and-paste. Just highlight the contents of the box, copy and past into a text file. Save the text file using any filename you wish. Then proceed with steps 4-6 above.
Your data should appear in your spreadsheet, and can be manipulated as in any spreadsheet.
Copy a few lines of the data from your spreadsheet below, and indicate what spreadsheet you are using:
series of regular breaths time at beginning of inhalation 1.14.15
event number clock time time interval
1 422.2422 422.2422
2 427.5469 5.304688
3 432.8359 5.289063
4 440.0703 7.234375
5 445.9531 5.882813
6 451.5391 5.585938
7 457.8906 6.351563
8 464.8906 7
9 471.5313 6.640625
10 478.8984 7.367188
11 484.2031 5.304688
Microsoft Excel 2010
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If the program was accurate to within .0001 second, then it would be unlikely that any of the times would repeat. For example .15625 seconds repeats five times. That would be extremely unlikely at your indicated level of accuracy.
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*#&!*#&!
&#Good work. See my notes and let me know if you have questions. &#