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course Phy 232
Starting with the cap in place on an empty bottle, siphon water from an adjacent full bottle. Allow the siphon to run a few minutes until the water levels in the two bottles stabilize. Estimate the percent change in the volume of the air in the capped bottle.
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About 25%.
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Estimate the percent change in the number of molecules in the air within the capped bottle.
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None of the molecules resulting in 0%.
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Estimate the percent change in the volume of the water in the open bottle.
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Approximately 50%.
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What do you think is the percent change in the air pressure in the capped bottle?
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About 20%.
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What is the difference in the two fluid levels?
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There is no difference, both levels are equal.
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What is the percent change in the number of air molecules in the capped bottle?
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0%, the air molecules don’t change throughout the process.
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Raise the open bottle as high as possible without disturbing the capped bottle. Allow time for the water levels in the two bottles to stabilize.
What percent of the volume of the capped bottle do you now estimate is occupied by water?
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About 50%, water flowed from the open bottle into the capped bottle.
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Estimate the percent change in the number of molecules in the air within the capped bottle.
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0% because no air could escape from the bottle with the cap.
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By what percent do you estimate the pressure in the capped bottle exceeds the original pressure (i.e., the pressure when the bottle was first capped)?
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50% because squeezing the bottle caused an increased pressure.
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What percent of the uncapped bottle do you estimate is now occupied by air?
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The bottle is about 25% full with water, therefore 75% is taken up by air.
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What is the difference in the two water levels?
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The water level of the open bottle is lower than the water level in the closed bottle. This is because the open bottle is being raised up.
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Return the uncapped bottle to the tabletop. What happens?
What is now the difference in the two water levels?
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Water now flows back into the capped bottle from the open bottle until the water levels are the same again.
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What do you think is the pressure in the uncapped bottle as a percent of its original pressure (before the bottle was capped)?
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The water would continue to run into the capped bottle, filling it up until the pressure inside of the capped bottle is close to or equal to the pressure outside of the bottle. It is hard to estimate the exact percentage of pressure change though.
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&#Your work on this lab exercise is good. Let me know if you have questions. &#