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PHY 201
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 **
2/9/2015 11PM
** **
1 hour
** **
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.
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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:
event number,clock time,time interval
1 , 46.375 , 46.375
2 , 46.45313 , 0.078125
3 , 46.53125 , 0.078125
4 , 46.66406 , 0.1328125
5 , 46.74219 , 0.078125
6 , 46.82813 , 0.0859375
7 , 46.9375 , 0.109375
8 , 47.03906 , 0.1015625
9 , 47.13281 , 0.09375
10 , 47.23438 , 0.1015625
11 , 47.35156 , 0.1171875
12 , 47.42188 , 0.0703125
13 , 47.65625 , 0.234375
14 , 47.85156 , 0.1953125
15 , 47.96094 , 0.109375
16 , 48.07031 , 0.109375
17 , 48.16406 , 0.09375
18 , 48.375 , 0.2109375
19 , 48.46875 , 0.09375
20 , 48.60938 , 0.140625
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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:
explanation:
.11759895
The easy way to get the average of 20 clicks would be to subtract the first clock time from the last, then divide that by the number of intervals.
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Good.
Those are, incidentally ,very quick times.
I actually think you're even quicker than that. It's clear that some of your intervals corresponded to missed clicks.
Mean times under .1 second are rare, though not unheard of.
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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):
.0703125,1
.078125,3
.0859375,1
.09375,3
.1015625,2
.109375,3
.1171875,1
.1328125,1
.140625,1
.1953125,1
.2109375,1
.234375,1
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You are welcome make any comments or ask any question about the process so far.
No comments 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 program reported multiples of some times, because of issues with programming/hardware. I would guess the most likely issue is with the input device, the mouse, and the way it is polled by the computer at certain intervals. A graph of all possible times would not be continuous.
This issue with accuracy shouldn't cause any issues with our physics experiments, because as shown by the 20 initial times recorded, the maximum resolution is very near the speed at which a human can possibly click. This error is smaller than other errors introduced into the system during any physical experiment.
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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 us the variation between the listed time interval and the interval between the next 2 points.
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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:
11.04688
11.1875
10.97656
13.36719
12.71875
11.96875
13.57813
12.96875
13.58594
13.9375
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If you have any comments please insert them here
No comments so far.
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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?
We did not measure any similar interval lengths because we are now outside the limitations of the input system, and getting real data. It is extremely unlikely that any two breaths taken would be the same length, down to a 100,000th of a second.
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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:
I would say C is the safest answer. When approaching .0001 second intervals, there is a higher likelyhood of reaching that hardware/software limitation. Also, the weakest link in the timing chain is the human reaction time registering the need to click the mouse button, and actually clicking the mouse button.
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The fact that a number of your intervals , including .078125, .109375, .09375 repeated a number of times out of 20 intervals makes it very unlikely that the resolution is .001 second. That resolution would imply about 60 possible intervals between .078 and .132 seconds. A repetition or two would be possible on 20 trials with 60 possible results, but the number of repetitions you observed is more consistent with a resolution of about .01 second.
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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 theQuestion 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:
I have copied a few lines from the .csv imported spreadsheet from Open Office Calc (the Excel equivalent) software. When copying and pasting the spreadsheet, it seems to be pasting an OLE style object, which I'm not sure will come through when I submit this.
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You need to sopy your document into a text editor to see what its format will be, then into the form. if the format is OK.
As you will be able to see, most of the format was OK, but your tables did not appear in the form of tables.
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Good work on the exercise. Do check my notes on the resolution of the TIMER program.
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