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.
** #$&* Your General Comment **
** #$&* Describe what you see on your first 10 clicks **
About 30 minutes
** #$&*Your TIMER data from 20 fast clicks **
This experiment is self-explanatory. Student report time of completion ranging
from 10 minutes to 1 hour, with 30 minutes being the most typical.
Copy this document into a text editor (e.g., Notepad; preferably NOT into a word
processor or html editor, e.g., NOT into Word or FrontPage).
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.
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.
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, but the .exe option is preferable.
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 .
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 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.
It lists time intervals at the times the button was clicked 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 intervals
without a missed or delayed click.
Copy your data starting in the next line:
1 1.21875 1.21875
2 1.359375 .140625
3 1.492188 .1328125
4 1.640625 .1484375
5 1.78125 .140625
6 1.929688 .1484375
7 2.070313 .140625
8 2.203125 .1328125
9 2.359375 .15625
10 2.5 .140625
11 2.640625 .140625
12 2.78125 .140625
13 2.929688 .1484375
14 3.070313 .140625
15 3.21875 .1484375
16 3.359375 .140625
17 3.507813 .1484375
18 3.664063 .15625
19 3.796875 .1328125
20 3.945313 .1484375
21 4.070313 .125
#$&*
You got at least 20 time intervals. Based on your data what was the average of
the first 20 time intervals? Note that you could get this average by averaging
the first 20 intervals. My first few intervals were .15625, .15625, .1875,
.171875, etc; I could just add up the first 20 intervals and divide by 20 to get
the average. However there is an easier and quicker way to get the result, so
use the easier way if you can.
Give your result, number only, in the first line, and starting in the second
line explain how you got it.
0.142578125
Added the numbers and divided by 20
#$&*
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.
.140625, 8
.1328125, 3
.1484375, 6
.15625, 2
.125, 1
#$&*
You may make any comments or ask any question about the process so far in the
box below
#$&*
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 noticed that the times all ended in 0 or 5 which means you are using a certain
amount of fractions of a second that you are rounding to.
#$&*
Here are a few more lines of data, with an added column showing the difference
between each time interval and the next.
clock time time interval difference from one time interval to next
9 13.10938 0.1875 -0.01563
10 13.28125 0.171875 -0.01563
11 13.4375 0.15625 0.03125
12 13.625 0.1875 -0.01563
13 13.79688 0.171875 0.015625
14 13.98438 0.1875 0.015625
15 14.1875 0.203125 -0.03125
16 14.35938 0.171875 -0.01563
17 14.51563 0.15625 0.03125
Take a good look at that last column and tell us what you see in those numbers,
and what this tells you about the TIMER program
It records the rate of change in time between each click.
#$&*
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:
1293.766
6.6875
7.351563
7.820313
7.367188
6.882813
8.679688
7.460938
7.804688
7.492188
7.75
#$&*
If you have any comments please insert them here
#$&*
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?
With smaller time intervals you have more of a rhythym than with larger ones
thus you have a higher chance of getting a different interval if you wait longer
between clicks.
#$&*
Which of the following statements do you think is the most accurate?
a. The TIMER program is capable of determining the time between two events
accurately to within about .1 second.
b. The TIMER program is capable of determining the time between two events
accurately to within about .01 second.
c. The TIMER program is capable of determining the time between two events
accurately to within about .001 second.
d. The TIMER program is capable of determining the time between two events
accurately to within about .0001 second.
Enter your answer and your reasoning below:
B. Because the program only calculates the time to the third significant digit
#$&*
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:
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.
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:
timerIntro
event number clock time time interval
1 1293.766 1293.766
2 1300.453 6.6875
3 1307.805 7.351563
4 1315.625 7.820313
5 1322.992 7.367188
6 1329.875 6.882813
7 1338.555 8.679688
8 1346.016 7.460938
9 1353.82 7.804688
10 1361.313 7.492188
11 1369.063 7.75
#$&*
Your instructor is trying to gauge the typical time spent by students on these
experiments. Please answer the following question as accurately as you can,
understanding that your answer will be used only for the stated purpose and has
no bearing on your grades:
Approximately how long did it take you to complete this experiment?
About 30 minutes not counting distractions.
&#Your work looks good. Let me know if you have any questions. &#