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'? **
When I squeeze the bottle, water moves up through the vertical tube and the water in the U of the pressure tube moves further to the capped end, but just barely. The higher the water travels, the harder it becomes to squeeze and the further the meniscus moves through the pressure tube. When I let go, the water comes down the vertical tube and the water in the pressure tube returns to approximately its initial position.
** Length of the air column in units of your measuring device: **
I have chosen to use the single-reduced copy because it has the least optical distortion and is easy for me to read.
** 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. **
29 cm, not including the cap
I placed the measuring device at the edge of the liquid and measured to the end of the air column at the cap. The measurement at the edge of the water was 10cm and the end of the tube was at 39cm. Therefore, the air column was 29cm long. Since the tube was level, it was very easy to measure the air column.
** 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. **
10cm
29cm
11.1, 11.7
11.2, 11.7
11.1, 11.6
11.3, 11.7
11.2, 11.6
This data shows that when I make the water reach 10cm above water level, the pressure in the container increases and pushes the meniscus further to the capped end. The average distance the meniscus moves is 0.5cm from its original position.
** 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. **
20cm
28.8cm
11.1, 11.9
11.0, 11.8
11.2, 12.0
11.1, 11.9
11.1, 11.8
When I compare this data to the previous data, I see that when I push the water up a longer distance through the vertical tube, pressure increases. This is evident from the increased distance the meniscus traveled in these trials with an average of .78cm.
** 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. **
60cm
28.7cm
11.0, 12.9
11.1, 13.0
10.9, 13.1
10.9, 13.2
11.0, 13.2
In these trials, the meniscus moved an average of 1.7cm. This is a little more than double the distance the meniscus moved at 20cm height. This shows that much more pressure was produced when I squeezed the water to 60cm rather than 20cm.
** **
40cm
28.5cm
11.1, 12.4
11.0, 12.5
11.1, 12.5
11.0, 12.4
11.1, 12.4
For these trials I squeezed the bottle to move the water 40cm up the vertical tube which is halfway between the two previous heights (20cm and 60cm). The average distance the meniscus moved at this height was 1.42cm. This average is almost halfway between the averages at the other two heights (.78cm and 1.7cm). This leads me to believe that the relationship between vertical distance and pressure is directly proportional and linear.
&#Your work looks very good. Let me know if you have any questions. &#