Instructions:

Read Introduction to "Water Barometer Investigation Assignment." View the video "Water Barometer Trial Video" as many times as you need to. Pretending that you (not Doug) carried out the Water Barometer Trial shown in the video, write up a good first draft of the report on this trial. To get students started and offer a structural framework, an incomplete version is supplied. The black print on this version is completed for you--leave it alone. Thered print is guidance. Students need to replace thered print with their own words. There should be no red print in your submission. This means none of the red text Doug provides for you should be in the draft you submit and nothing should be in red. For more guidance on writing this report, recall/review Module 1.1, Submit a first draft of the report by the deadline as either a WORD or PDF file. As this is your first go, perfection is not expected. Students will have a chance to perfect their work in the final draft in Module 1.4. Students who do submit perfect (or nearly so) work here are exempt from Module 1.4.

GEOG1101 Physical Geography

Date

Test of Water Barometer

Purpose:

Explain how a liquid-filled barometer works and a little bit of the history of how scientists have come to understand this. Offer at least two citations in this section. The two references below should be enough but feel free to consult others. Describe the relationship between the heights of mercury-filled and water-filled barometers. Explain what is being testing and why. This section should be no more than 150 words.

Hypothesis:

Under similar atmospheric conditions, at the same time and place, the height of a water-filled barometer will be approximately 13.5X higher than a mercury-filled barometer, plus or minus 10% to account for minor error.

Method:

Materials:

List the materials--five or six items.

Procedure:

Offer enough detail so that another researcher could repeat trial/verify results. Specify what data is recorded. Pretend as if you carried out the trial that Doug did on the video. The mercury barometer is at NCC in room S1310 and the stairwell is in the Science Building This section should not exceed 200 words.

Calculations:

Explain the math so that another could repeat/verify. Offer formulas if needed. No more than a couple sentences.

Data and Results:

This is a simple listing of data and results. No need for much write-up.

Conclusion:

Remind reader of the hypothesis then explain whether or not the results support it. No more than 100 words are necessary.

Discussion:

Explain to the reader why you think the results came out as they did. Describe any unexpected observations or outcomes. Identify possible sources of error and suggest ways to improve the barometer or future experiments. This section should be between 100 and 200 words.

References:

Chemical Education Division Group, College of Science, Purdue University. (2021). Evangelist Torricelli. In Scientist Index. http://chemed.chem.purdue.edu/genchem/history/torricelli.html

Mason, J.A., Burt, J., Muller, P.O., & DeBlij, H.J. (2016). Physical Geography: The global environment. Oxford University Press.

Introduction to Water Barometer Lab

It's long accepted that on Earth's surface is atmospheric pressure and that a liquid-filled barometer is an effective instrument for measuring this pressure. Also, since Galileo and Torricelli published their findings in the mid-17^th century, it is established that the height of a liquid-filled barometer is equivalent to the pressure exerted by weight of the atmosphere: essentially, holding area constant, the weight of the atmosphere equals the weight of the liquid column. It follows, holding pressure constant, the height of the liquid column would be inversely proportional to the liquid's density. In other words, a barometer filled with a liquid half as dense mercury would be twice as tall under the same atmosphere. Likewise, because the density of mercury is approximately 13.5 g/ml and the density of water is 1.00 g/ml, it takes 13.5X more water (by volume) to weight the same as mercury and therefore, under constant atmospheric pressure, a water-filled barometer would be 13.5X higher than a mercury-filled. This is all considered scientific fact.

In the spirit of falsifiability, to be considered scientific, a fact must be falsifiable. In this trial, we propose a test which could falsify the scientific regarding atmospheric pressure and liquid-filled barometers. Of course, because so much scientific work has verified and re-verified these facts over centuries, the likelihood of this trial actually falsifying these facts is infinitesimally small. Nonetheless, because the strength of science is built upon the work of skeptics, we will attempt to falsify Torricelli and consequently either strengthen, or weaken, the veracity of his findings.

In this investigation, we measure atmospheric pressure using a mercury-filled barometer, predict the height of a water-filled barometer by multiplying times 13.5, then we build a water barometer and test our prediction. If the water barometer results are with 10% of the predicted height (to allow for experimental error and other unknowns) we will consider our results consistent with Torricelli.

The procedure for the water barometer test has already been carried out and is posted on the attached video. The student's job here, after reviewing the water barometer trial, write-up a first draft of the lab as if the student had done the trial.

To offer students guidance, an incomplete version of the report is provided. Black print is permanent and should not be changed. Red printoffers guidance and should be replaced with the students' words. Students may also consult the template offered in Module 1 for guidance.

A lecture on atmospheric pressure is offered under Content>Labs>Module 2.