Early Elementary #3

2nd grade

 

What Time Is It?

 

1.  What is the question I wanted to answer?

   Which watch works best?

 

2.  What did I think would happen?

My hypothesis is that model# wr30m will work best.

 

3.  What materials did I use?

9 quartz watches, a camera, the internet, notebook.

 

4.  What did I do to answer my question?

I got 9 watches and 3 kinds of watches (wr30m, xj-706, & ion).   I set the watches to approximately the right time.

Then I took pictures of the watches next to the official time at www.time.gov.

Then I wrote down the times in my notebook and then I compared the watch times with the real time. I waited for one month. Then I took pictures again. Then I wrote them down in my notebook. Then I compared the times from the beginning and the end. And then I calculated which watch worked best.

.

5.  What are my variables?

            a)  What did I change? (Independent Variable)

The kind of watch.

            b)  What changed as a result of what I did? (Dependent Variable)

The drift.

            c)  What things did I keep the same? (Controlled Variables)

Time I was comparing to, the length of time, all quartz,

 

6.  What is the answer to my question?

 

watch number:

wtime

c time

ahead

behind

w time

c time

ahead

behind

change:

wr30m

3

4:04:19

4:04:35

######

0:00:16

10:31:24

10:31:54

######

0:00:30

0:00:14

ss

wr30m

2

4:13:31

4:13:37

######

0:00:06

10:32:59

10:33:26

######

0:00:27

0:00:21

ss

wr30m

1

4:19:37

4:19:53

######

0:00:16

10:34:40

10:34:55

######

0:00:15

0:00:01

sf

ion

4

6:39:01

6:39:30

######

0:00:29

11:14:03

11:06:07

0:07:56

######

0:08:25

mf

xj-706

9

7:22:29

7:22:29

0:00:00

0:00:00

11:09:26

11:09:36

######

0:00:10

0:00:10

ss

xj-706

7

7:33:04

7:32:30

0:00:34

######

11:14:41

11:13:38

0:01:03

######

0:00:29

mf

ion

6

7:39:22

7:38:59

0:00:23

######

11:26:09

11:17:35

0:08:34

######

0:08:11

mf

ion

5

7:50:04

7:49:45

0:00:19

######

11:38:21

11:30:32

0:07:49

######

0:07:30

sf

xj-706

8

14:12:23

7:52:34

6:19:49

######

18:00:45

11:40:49

6:19:56

######

0:00:07

sf

 

Wr30m and xj-706 are best.

 

7.  What books or other information did I use to help me?

Lombardi, Michael. The accuracy and stability of quartz watches.horological journal. Feb. 2008.pp.57-59.

http://en.wikipedia.org/wiki/watches

www.time.gov