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.
** Your General Comment **
** Describe what you see on your first 10 clicks **
Clicking the button causes the timer program to take recordings. The recordings seem to be the total time the timer program has been running and the time since the previous click.
** Your TIMER data from 20 fast clicks **
1 1.488281 1.488281
2 1.65625 .1679688
3 1.835938 .1796875
4 2.019531 .1835938
5 2.1875 .1679688
6 2.359375 .171875
7 2.539063 .1796875
8 2.710938 .171875
9 2.890625 .1796875
10 3.0625 .171875
11 3.242188 .1796875
12 3.425781 .1835938
13 3.632813 .2070313
14 3.824219 .1914063
15 3.996094 .171875
16 4.175781 .1796875
17 4.359375 .1835938
18 4.550781 .1914063
19 4.746094 .1953125
20 4.929688 .1835938
21 5.113281 .1835938
22 5.292969 .1796875
** Your average time interval for 20 time intervals **
0.1721
I subtracted the total time value at the 20th interval from the original interval. This gave me 4.9297-1.488281=3.4414. I then divided this by 20 which gave 0.1721.
** Your frequency distribution for the 20 time intervals (interval, number of times it was observed) **
.1679688, 2
.171875,4
.1796875, 6
.1835938, 5
.1914063, 2
.1953125, 1
.2070313, 1
** Your general comment to this point **
Should I just ignore the initial time when calculating my average?
** Why did you observe only certain time intervals? **
The time program is flawed, but not useless. There is a certain amount of error in any recording device. The timer probably recorded this number frequently because it counts in certain intervals or is programmed to round to this number.
** What did you see when you looked at the differences between time successive time intervals? **
The numbers in this column show more similarity then the numbers in the previous column. The clock seems to go up by intervals of .01563. This is indicated by the appearance of .01563 and (.01563)(2) which is .01325.
** Your time intervals for 7 complete breaths: **
1.675781
15.56641
20.66797
19.56641
14.78125
15.55469
18.29297
15.98047
16.82422
12.94922
** Your general comment to this point: **
** Why did you rarely, if ever, observe that same time interval twice? **
Since breathing occurs over a longer period of time, more intervals .01563 can occur. The longer periods of time causes there to be fewer or no repeats because there is more variability in breathing and the variables are greater times.
** Do you think this program is accurate to .1 or .01 ... **
b. the timer counts up by .01563, therefore while there will be the variability of the .00563, it will be ABOUT accurate. There is significant variability so if looking for the exact accuracy of the timer it should only be taken to the .1 sec.
** Copy of a few lines of your spreadsheet from the TIMER program. **
event number clock time time interval
1 1.675781 1.675781
2 17.24219 15.56641
3 37.91016 20.66797
4 57.47656 19.56641
** **
40 minutes
** **
Very good work. You are already demonstrating a lot of insight (e.g., it is rare that a student correctly identifies the .015.... second interval; note also that this interval is 1/64 second; because of the binary nature of the computer we might expect that the interval is a power of 2.