#$&*
Phy 121
Your 'timer program' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
#$&* Your General Comment **
#$&* Describe what you see on your first 10 clicks **
About an hour
#$&*Your TIMER data from 20 fast clicks **
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.
#$&*I see a list of 1 through 10. Beside the number, I see two decimal numbers. For example beside number one, is the
number 27.87109 and that number is repeated. Number two contains numbers 28.15234 and .281125.
Now click on Initialize Counter, which will clear all the data from the timer window. Click the mouse as fast as you can until the TIMER window fills up. Be sure you get at least 20 time intervals.
If you miss a click, try again. Keep trying until you get at least 20 intervals without a missed or delayed click.
Copy your data starting in the next line:
#$&*
1 264.3789 264.3789
2 264.5508 .171875
3 264.6719 .1210938
4 264.8984 .2265625
5 265.0586 .1601563
6 265.2188 .1601563
7 265.3516 .1328125
8 265.5859 .234375
9 265.7969 .2109375
10 265.9648 .1679688
11 266.1172 .1523438
12 266.2305 .1132813
13 266.4922 .2617188
14 266.6641 .171875
15 266.832 .1679688
16 267.1055 .2734375
17 267.3281 .2226563
18 267.5313 .203125
19 267.7148 .1835938
20 267.875 .1601563
21 267.9961 .1210938
22 268.1172 .1210938
23 268.2695 .1523438
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.
#$&*13.3934
@&
Your time quick-click time intervals were all less than .30 seconds, and most were less than .20 seconds. The mean of the time intervals cannot be longer than the longest of the intervals.
So clearly the average of your quick-click intervals is not 13.39 seconds.
Note also that the first interval in the third column is very clearly not a quick-click interval.
How many quick-click intervals did you observe, and how would you therefore calculate the mean of your observed quick-click intervals?
Note also that given the time intervals between your quicker clicks, it's likely that an apparent interval longer than .25 seconds was the result of a missed click. To get a valid observation of quick clicks you would redo the clicking until you obtained data that did not include any missed clicks. However your data will work for the purposes of the present exercise, so you are not asked to redo anything except the calculation of the mean quick-click interval.
*@
I added the numbers through 20 and then I divided them by twenty.
What different time intervals did you observe in your first 20 intervals, and how many times did each occur?
List below the different time intervals you observed and the number of times each occurred. List from the
shortest to the longest interval, and use a comma between the time interval and its frequency.
#$&* .171875, 2
.1210938, 3
.1523438, 2
.1601563, 2
.1679688, 2
@&
Good, but your list accounts for only 11 of the intervals you reported.
*@
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?
#$&* I think it reported the time so frequently because it was the average time it took the individual to
click between intervals. Like everything in this life, the timer program may be a bit flawed. However this doesn't mean it's useless.
I don't think the timer program was even fast enough to get the exact intervals for how many seconds it took someone
to click. I think that the best thing to do is estimate and guess the aproximate amount of seconds it took
the individual to click.
Here are a few more lines of data, with an added column showing the difference between each time interval and the next.
clock time time interval difference from one time interval to next
9 13.10938 0.1875 -0.01563
10 13.28125 0.171875 -0.01563
11 13.4375 0.15625 0.03125
12 13.625 0.1875 -0.01563
13 13.79688 0.171875 0.015625
14 13.98438 0.1875 0.015625
15 14.1875 0.203125 -0.03125
16 14.35938 0.171875 -0.01563
17 14.51563 0.15625 0.03125
Take a good look at that last column and tell us what you see in those numbers, and what this tells you about
the TIMER program
#$&* The third column has mostly negative numbers. The numbers usually start with -.01 or .01. This tells us that
the timer isn't completly accurate when it comes to the number of seconds it takes for us click from one interval
to the next.
Now initialize the TIMER once more, and take a series of 10 relaxed breaths. Every time you start to inhale,
hit the TIMER button.
#$&* 13.26953
1.738281
2.988281
5.242188
2.367188
3.5
3.503906
5.632813
4.84375
5.347656
Most likely you did not observe the same exact time interval twice, and if you did it did not happen nearly
as often as when you did the fact clicks.
Why do you think this is exactly what we would expect?
#$&* Because we don't breathe the exact same time as we may click. They are different muscles used.
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:
#$&* I would go with Statement B, because most of the intervals recorded were within .01 seconds or -.01 seconds.
Note that the TIMER.exe program can save your data in a format that can be read by a spreadsheet
(the TIMER applet cannot do so).
Copy a few lines of the data from your spreadsheet below:
#$&* event number clock time time interval
*#&!
@&
Good work overall.
However see my notes. You are asked to correct your result for the average time interval, and for future reference you should also think about other details mentioned in the notes.
&#Please see my notes and, unless my notes indicate that revision is optional, submit a copy of this document with revisions and/or questions, and mark your insertions with &&&& (please mark each insertion at the beginning and at the end).
Be sure to include the entire document, including my notes.
If my notes indicate that revision is optional, use your own judgement as to whether a revision will benefit you. &#
*@