Phy 232
Your 'measuring atmospheric pressure' 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 comment **
** How does the system behave and how does it 'feel'? **
The air column shortens as the water level in the vertical tube rises. It actually doesn't shorten as quickly as I thought it would (the air column), though. It's hard to tell if it shortens linearly with the vertical tube or at a decreasing rate.
** Length of the air column in units of your measuring device: **
I chose the singly reduced ruler, since it was the most reduced ruler that I could use and still measure the entirety of the distance I needed to measure (the others were too small to measure the entire distance in one spread).
** Your report of the vertical position of the first mark relative to the water surface of the first mark, the length of the air column in units of your selected measuring device, and the two meniscus positions observed with each of your five trials. **
28.9cm
I measured from the meniscus (1 cm) to the barrier (29.9 cm).
** Your report of the vertical position of the second mark relative to the water surface of the first mark, the length of the air column in units of your selected measuring device, and the two meniscus positions observed with each of your five trials. **
15cm (or 10 real cm)
28.9 cm
1cm, 2.5 cm
1cm, 3 cm
1cm, 3.1 cm
1cm, 2.8 cm
1cm, 2.8 cm
If these are the changes in the position of the meniscus, then, on average, the water column is shortened by about 1.8cm (or 1.2 real cm). I thought it would be more, honestly.
** Your report of the vertical position of the highest mark relative to the water surface of the first mark, the length of the air column in units of your selected measuring device, and the two meniscus positions observed with each of your five trials. **
30cm (or 20 real cm)
27.1cm
2.8cm, 4 cm
2.8cm, 4 cm
2.8cm, 4.2cm
2.8cm, 3.9cm
2.8cm, 4.2cm
On average, the air column decreased by about 1.3 cm, or about 2.5cm since its original position. Hmmm.
** Your report of the vertical position of the 'in-between' mark relative to the water surface of the first mark, the length of the air column in units of your selected measuring device, and the two meniscus positions observed with each of your five trials. **
45 cm (or 30 real cm)
25.8cm
4.1cm, 5cm
4.1cm, 4.9cm
4.1cm, 5.2cm
4.1cm, 5.3cm
4.1cm, 4.8cm
On average, this time the air column changed by about 1cm. I'm a little worried I have something hooked up wrong since it didn't change by much in any of the trials. But according to these results, the air column is decreasing at a decreasing rate.
It appears you have reported the average of the last meniscus positions, and the new meniscus positions.
That's OK; however you were asked for the positions relative to the 'first mark', which would be the very first mark you made, at the 1 cm position.
Either way, you will be able to easily enough find the average length of the air column for each trial.
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1.5 hr
&#Your work looks good. See my notes. Let me know if you have any questions. &#