#$&*
phy 121
Your 'timer program' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
** TIMER program_labelMessages **
12:35 11/18/13
** **
25 minutes
** **
Now click on Initialize Counter, which will clear all the data from the timer window. Click the mouse as fast as you can until the TIMER window fills up. Be sure you get at least 20 time intervals.
If you miss a click, try again. Keep trying until you get at least 20 quick-click intervals without a missed or delayed click.
Copy your data starting in the next line:
1 227.3281 227.3281
2 227.5469 .21875
3 227.7344 .1875
4 227.9063 .171875
5 228.1094 .203125
6 228.3125 .203125
7 228.5469 .234375
8 228.7656 .21875
9 228.9531 .1875
10 229.168 .2148438
11 229.4023 .234375
12 229.5898 .1875
13 229.8086 .21875
14 230.0117 .203125
15 230.1992 .1875
16 230.418 .21875
17 230.6523 .234375
18 230.8398 .1875
19 231.0586 .21875
20 231.2773 .21875
21 231.5078 .2304688
22 232.5078 1
#$&*
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: 0.20898438
explanation: I had 20 time intervals (#1 and #22 not included) I added up these 20 intervals and divided by 20 to get the average.
#$&*
@&
Good. Note that you could also have subtracted clock time 1 from clock time 21 and divided by 20.
*@
When I did this activity the first few lines of my data were as follows:
event number clock time time interval
1 11.67188 11.67188
2 11.875 0.203125
3 12.0625 0.1875
4 12.20313 0.140625
5 12.375 0.171875
6 12.54688 0.171875
7 12.73438 0.1875
8 12.92188 0.1875
9 13.10938 0.1875
10 13.28125 0.171875
11 13.4375 0.15625
It looks like the same intervals keep popping up. For example .1875 seconds occurs 5 times out of the first 10 intervals, .171875 seconds occurs three times, and .203125 seconds, .140625 seconds and .15625 seconds each occur once.
A frequency distribution for my time intervals would be as follows:
time interval frequency
,140625 1
.15625 1
.171875 3
.1875 5
.203125 1
What different time intervals did you observe in your first 20 intervals, and how many times did each occur? List below the different time intervals you observed and the number of times each occurred. List from the shortest to the longest interval, and use a comma between the time interval and its frequency. For example my data above would be listed at
.140625, 1
.1565, 1
.171875, 3
.1875, 5
.203125, 1
The above list is called a frequency distribution. Be sure you make note of this terminology.
Your list should be in exactly the above format, with no other symbols or characters.
Your list (i.e., your frequency distribution): Alicia’s List
0.171875, 1
0.1875, 5
0.203125, 3
0.2148438, 1
0.21875, 6
0.2304688, 1
0.234375, 3
#$&*
You are welcome make any comments or ask any question about the process so far.
I understand everything thus far
#$&*
On the 10 intervals I've shown you, do you really think I managed to get a time of .1875 seconds, accurate to 4 significant figures, on half of the intervals? If you do, I'm grateful for your confidence but I'm just not that good. No human being has that much neurological and muscular control.
So why do you think the TIMER program reported that time so frequently? Why weren't there times like .1830 seconds, or .1769 seconds? Does this mean that the TIMER program is flawed? Does that mean it's useless?
Why did the TIMER report .1875 seconds multiple times; your conclusions about the program:
I think the TIMER program has frequently repeated intervals because of rounding. There weren’t times like .1830 or .1769 because the program doesn’t round to only 4 decimal places but up to 7 decimal places. The TIMER program is certainly not useless, I can think of many uses in physics and in other life events during which the timer would be useful. I wouldn’t say the program is flawed, I would just say because of the program not rounding, the same data is reported frequently.
#$&*
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 see both Positive and negative differences. The program is keeping track of not only the time difference, but also whether the time elapsed between events is increasing or decreasing.
#$&*
Now initialize the TIMER once more, and take a series of 10 relaxed breaths. Every time you start to inhale, hit the TIMER button.
My results for the first 7 complete breaths are as follows:
series of relaxed breaths
event number clock time time interval difference between time interval and next
1 1569.734 1569.734
2 1582.75 13.01563 0.32812
3 1596.094 13.34375 3.90625
4 1613.344 17.25 2.70313
5 1633.297 19.95313 1.35937
6 1654.609 21.3125 4.23438
7 1680.156 25.54688 2.15625
8 1707.859 27.70313
I didn't go on because the time between my breaths kept increasing, and I was afraid if I relaxed any more I might stop breathing altogether. It's going to take either more statistical analysis to determine whether that's a real danger, or a little common sense.
Report your results by just entering your time intervals, one to each line, in the box below. If I was entering my results I would enter
13.01563
13.34375
17.25
19.95313
21.3125
etc.
Enter your results in the same format:
10.21875
14.64844
14.57031
15.34766
15.63281
17.97266
15.42578
16.16406
17.8125
#$&*
If you have any comments please insert them here
Good so far
#$&*
Most likely you did not observe the same exact time interval twice, and if you did it did not happen nearly as often as when you did the fact clicks.
Why do you think this is exactly what we would expect?
Because breathing takes longer and would be harder to repeat the same time interval. With the mouse clicking I was trying to click it fast but consistently
#$&*
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
@&
If the TIMER was accurate to .0001 second, it would be unlikely that any of the intervals would repeat. However many of those intervals repeat, and more than one do so multiple times.
*@
#$&*
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:
breaths relaxed
event number clock time time interval
1 5.195313 5.195313
2 15.41406 10.21875
3 30.0625 14.64844
4 44.63281 14.57031
5 59.98047 15.34766
6 75.61328 15.63281
7 93.58594 17.97266
8 109.0117 15.42578
9 125.1758 16.16406
10 142.9883 17.8125
Excel
#$&*
self-critique rating
@&
Very well done, but do check my two notes.
*@