Wednesday, May 23, 2012

Science Lab - Atmospheric Pressure

8th Grade - Physical Science

A. Purpose: In this experiment, the experimenter will demonstrate how the atmosphere exerts pressure on everything it encounters. Observations will be made of both the positive and negative consequences of atmospheric pressure. The experimenter will then discover why and how these consequences occurred. Finally, there will be nothing to do but marvel at how intelligently The Creator has built this world.

Air exerts pressure over the entire earth. That air is called atmosphere. The earth's atmosphere reaches up higher than 460km above sea level. All of this air pushes down on everything at the surface. Atmospheric pressure varies widely over the earth. These changes are extremely important when studying weather (Wikipedia). It is because of these changes that climbers have a difficult time breathing at high altitudes. (

As imagined by many people, all this air becomes quite heavy. In fact, every square inch of earth is being pressed down by an average weight of 14.7 pounds. As a result, there is an average weight of 176 pounds being pressed down on every fully-grown human being. The reason humans do not feel as if they are holding up 176 pounds is because God already has a solution for this heavy burden. Although the air around a person is pushing in on them, the air inside of them is pushing out. Therefore, the air inside and out cancel out each other and the person does not feel any weight pushing down on them.

This experiment hopes to show the reality of atmospheric pressure. The experimenter hopes to demonstrate this by observing and aluminum can in two very different situations. The first time the experimenter will study the can under normal conditions. The second time the can will be observed when no air is inside of it.

This experiment is of interest to science because the earth's atmosphere is a major ingredient for survival. Because the atmosphere is so important, it is necessary to try and understand everything about it possible. Atmospheric pressure is beyond important to science, it is indispensable. The sheer knowledge of it is useful to practically everything science explores.

Hypothesis: If the can is robbed of all the air it contains inside of itself and dumped upside down in the water so that no new air could not possibly enter back inside, then the atmospheric pressure on the outside will cause the can to implode.

B. Equipment:

2.Frying pan
3.Two empty, 12-ounce aluminum cans (like soda pop cans)
4.Two bowls
6.Ice cubes
8.Eye protection such as goggles or safety glasses

C. Procedure

1. Put a small amount of water in each aluminum can. You should use only enough to cover the bottom of the can with a small amount of water. The more water you use, the less dramatic the effect.
2. Place the two aluminum cans in the frying pan so that they stand up.
3. Put the frying pan on the stove and turn the heat up to “high”. This will heat up the water in the cans.
4. While you are waiting for the water in the cans to heat up, fill each bowl half full of water.
5. Place a few ice cubes in each bowl so that the water becomes ice cold.
6. Wait for steam to start rising out of the opening of each can. That will tell you when the water inside is boiling vigorously.
7. Once a steady stream of steam is coming out of each can, use the tongs to grab one can and place it upright in one of the bowls of water.
8. Note what happens.
9. Use the tongs to grab the other can and place it upside down in the other bowl of water.
10. Note what happens.
11.Clean up your mess.

D. Observations:

1. The two cans are filled with an extremely small amount of water from the faucet. Water is clear and the cans are completely empty.
2. Cans are placed on frying pan and stood up with little effort from the experimenter.
3. Frying pan is placed upon the stove without anything breaking. Water begins to heat up as expected.
4. Water in each can continues to heat up. Water from tap flows into both bowls. Water is clear and appears normal.
5. Ice cubes are clear and colorless. Bowls are now ¾ way full.
6. Steam begins to continuously stream out of both cans.
7. Plastic tongs are used to lift the first can. Can is then placed right side up in one of the bowls of ice water.
8. Leftover water in can quickly evaporates.
9. Same plastic tongs as used in step 7 are again used to pick up the second can. Can is turned upside down and quickly placed in the second bowl of ice water.
10. Can implodes with a very loud “bang”. After being lifted out of the bowl, a small amount of water spills out into the bowl.
11. Imploded can is kept in experimenters room while the undamaged can is thrown in the trash can, water and ice are dumped into the sink, and stove is turned of.
E. Conclusion:

The hypothesis above was confirmed. The experiment itself did not contain any noticeable faults. The steam in the aluminum can pushed out all of the air outside of it. The experimenter can conclude that because of the fact that there was no air in the can, it imploded as a result of atmospheric pressure forcing the aluminum inward. The experimenter may also conclude that because the air inside of people, humans, and all living things is pushing outward, that there will never be any danger thanks to The Creator's marvelous design for our survival.

This experiment may be improved by adding less water to the aluminum can. In doing so, more air can be removed. The less air in the can, the more noticeable of an implosion there will be. Also, a smaller can would serve as the same remedy for this issue.

Further research may also be tested after performing this experiment. This research could include why the steam in the can helps to remove the air. Also, it is crucial to understand why the water in the bowls must be ice cold. These are two critical components of this experiment that must be recognized.

F. Bibliography:

Rosenoff, Steven. Classroom Lecture. July 7, 2011

Wile, Dr. Jay L. Exploring Creation with Physical Science, 2nd Edition. Apologia Educational Ministries, Inc. 2007

Wikipedia contributors, “Atmospheric Pressure” Wikipedia, The Free Encyclopedia
Document: wiki/Atmospheric_pressure

Universe Today, “Atmospheric Pressure” Universe Today
Domain: http.//
Document: 44400/atmospheric-pressure/

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