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 **
I had trouble understanding the second portion of this lab. Perhaps if you made a step-by-step directional video it would help.
** How does the system behave and how does it 'feel'? **
By squeezing the bottle (thereby increasing pressure), the water in the tube increases in height--probably because the volume decreases. This may have something to do with PV=nRT, but I'm not sure because that formula is for gasses.
The system behaves the way it does because of the behavior of the gas in the system. The water is just an indicator of what's going on in the gas.
** Length of the air column in units of your measuring device: **
I am using the 1/2 scaled version because it is the largest so I think I can get the best reading.
you didn't report the length of the air column
** 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. **
About 2.55
I followed the instructions and took the measurements. Since the ruler appears to go to the tenths place, I took it to the hundredths place for significant digits.
** 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. **
2
2.35
3.10, 4.01
3.16, 4.10
3.14, 4.10
3.27, 4.20
3.16, 4.11
This is the information I obtained from the first experiment.
** 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. **
3
3.01
5.21, 6.01
5.25, 6.07
5.30, 6.14
5.27, 6.20
5.29, 6.30
This is the information I obtained from the second experiment.
** 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. **
4
2.97
7.26, 8.10
7.35, 8.15
7.25, 8.12
7.19, 8.16
7.25, 8.13
This is the information I obtained from the third experiment.
** **
5
2.97
9.25, 10.32
9.35, 10.30
9.26, 10.36
9.22, 10.35
9.29, 10.42
This is the information I obtained from the final experiment.
** **
About 1.75 hours
The vertical marks on the tube were to have been separated by 10 cm. You report vertical positions which differ by only a centimeter or so. If this is indeed the case, then your data won't be sufficiently differentiated to give you useful results in the second part of this experiment.
Can you clarify in a couple of sentences what your vertical measurements represent?
The reported length of the air column in the tube doesn't seem to correspond to the situation. Can you also clarify that?
I agree that a bit more visual information might be helpful. However note that the more explicitly I show what is to be done, the more students will tend to imitate it without thinking about it, and the closer we get to traditional 'cookbook'-style labs.
I'll also be glad to answer specific questions about the second part of the lab.