timer program

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 **

Tuesday August 4 - 12:50PM

** Describe what you see on your first 10 clicks **

There are 3 columns:

The first is the number of clicks I have hit. The second is the total time spent since the beginning of the program, and the third is the amount of time between clicks.

** Your TIMER data from 20 fast clicks **

1 1.84375 1.84375

2 2.03125 .1875

3 2.171875 .140625

4 2.34375 .171875

5 2.515625 .171875

6 2.6875 .171875

7 2.875 .1875

8 3.03125 .15625

9 3.21875 .1875

10 3.40625 .1875

11 3.5625 .15625

12 3.734375 .171875

13 3.90625 .171875

14 4.078125 .171875

15 4.25 .171875

16 4.421875 .171875

17 4.59375 .171875

18 4.78125 .1875

19 4.953125 .171875

20 5.125 .171875

21 5.296875 .171875

22 5.46875 .171875

23 5.65625 .1875

24 5.78125 .125

** Your average time interval for 20 time intervals **

Average - 0.240885417

You always need to check your results against common sense, and this one doesn't quite check out.

None of your quick-click time intervals was longer than .2 seconds, so the mean can't be .24 seconds.

Can you see what happened to give you this erroneous result?

I copied the data into Microsoft Excel and used the formula maker to find the average.

** Your frequency distribution for the 20 time intervals (interval, number of times it was observed) **

0.125 1

0.140625 1

0.15625 2

0.1875 6

0.171875 13

1.84375 1

1.84 seconds isn't a quick-click interval, as you've probably realized from my previous note.

** Your general comment to this point **

** Why did you observe only certain time intervals? **

It means we need to check for accuracy when we use it.

** What did you see when you looked at the differences between time successive time intervals? **

They consist of only 3 root numbers:

.01563, .3125, .015625 which are either positive or negative.

There all within 3 hundredths of a second.

The tenths is always 0.

** Your time intervals for 7 complete breaths: **

6.65625

11.15625

7.0625

9

8.296875

7.953125

7.8125

** Your general comment to this point: **

** Why did you rarely, if ever, observe that same time interval twice? **

The longer between clicks the more accurate it becomes.

** Do you think this program is accurate to .1 or .01 ... **

b. The TIMER program is capable of determining the time between two events accurately to within about .1 second.

Because when I got 13 - .171875's I realized how impossible it is to even get 13 - .17's, meaning it must only be accurate within .1 of a second.

Very good way to put it.

** Copy of a few lines of your spreadsheet from the TIMER program. **

event number clock time time interval

1 2259.344 2259.344

2 2260.156 0.8125

3 2260.953 0.796875

4 2261.719 0.765625

** **

30 minutes

** **

On the DVD, there is a timer program that also plots graphs of the time - is that to be used as well?

It isn't required but you may use it if you find it appropriate to a task.