Analytic Essay

Dry Experiment
What Results show
The results show that as you add one atmosphere of pressure to the air inside of the soda bottle, the length of the bubble should decrease by half. Then as another atmosphere of pressure is added to the soda bottle, the bubble should decrease to one third of the original volume. So as there is only one atmosphere of pressure on the bottle, the bubble is at its complete volume. With two atmospheres of pressure on the bottle, the bubble is one half of its original volume. With three atmospheres of pressure on the bottle, the bubble is one third of its original volume. This relationship of atmospheres of pressure on the graduated cylinder to the fraction of the original volume was shown as we pressurized the bottle to seven atmospheres.

Why These Results Relate to Scuba Diving
These results show how much scuba diving can affect your lungs. You have to exhale as you surface from any depth because the air inside of your lungs expands as less pressure is exerted on the air. If you hold your breath as you surface, the air inside of your lungs will expand past it's storage capacity depending on how deep you are. When we brought the tube back up to the surface, the air inside expanded to its original volume. This shows that if I diver takes a breath at the surface, and doesn't exhale on his ascent or descent, the air in his lungs will come close to the original volume of his breath.

Error Analysis
There are many errors that occurred in this experiment. First of all, when we sucked out some of the air from the graduated cylinder to make only twenty-five ml. of air inside the cylinder, there is no way to know for sure that there was exactly twenty-five ml. of air inside. This is because we examined the cylinder with only our eyes, and if we were off by just a little bit, the results would be altered. Also, since we just used our eyes to read the volume of the air inside the cylinder, there is no way to know how exact our readings were. When we pumped air into the bottle to exert different atmospheres of pressure on the cylinder, the top wasn't completely sealed, and some air was escaping as we were pumping. It was also hard to figure out if we had exactly the amount of pressure that we thought we had on the cylinder because the gauge on the pump is very small and is hard to make exact. When we conducted our experiment, the volume of the air was about two to three percent higher than our hypothesis predicted. This is because the pressure that we pumped into the bottle didn't get fully transferred into the bottle, and some of the pressure leaked through the cap.

Wet Experiment
What Results Show
The results from this experiment show the same thing as what was shown in the dry experiment, only we were only able to go down in increments of two feet, whereas in the dry experiment, we were able to use increments of atmospheres, which are similar two thirty-three feet of sea water. This experiment showed more detail as to what happens in the first one half of an atmosphere of depth. These results show that the change of length of the bubble is the most in the first two feet of descent.

Why These Results Relate to Scuba Diving
These results show that even when you are at a depth of sixteen feet, if you take a breath of compressed air, you still have to exhale as you surface to prevent lung damage. This happens because when you take a breathe of compressed air below the surface the air is still compressed inside of your lungs, but as you surface, Boyle' Law and our experiments show that the air will expand. If you already have your lungs full of air, then the expansion will damage your lungs because the air expands to a volume greater than that of the lung storage capacity. Breathing out as you surface prevents lung damage because the air that is being expanded is also being breathed out and so the volume is at a size that fits inside the lung storage capacity.

Error Analysis
Our results in this experiment gave us the approximate results that we wanted, although there was a margin of error. First of all, the tape measurer that was hung from the high diving board to the bottom of the pool was very hard to keep straight. When we originally started the experiment we had to start over again because the tape measure kept moving around and we couldn't get an accurate reading. To resolve this problem, we had Mr. How attempt to hold the end of the tape measure at the bottom of the pool. This, however, was a very hard job. It was hard for him to know when the tape measure was straight, because whenever he would look up to see all he would see was the bubbles that he was exhaling. Another problem with this experiment was that it was very hard to get an accurate reading of the bubble inside of the tube. The change didn't occur in too many centimeters of the bubble, so it was hard to get an accurate length perception underwater by using only our eyes. Our results for some depths were higher than our hypothesis predicted, and for other depths were lower than our hypothesis predicted. Although the results were somewhat off from our hypothesis, we got the data that we were looking for that shows Boyle's Law.

All in all, these experiments gave us the data that we were looking for. It was very fun doing both experiments. Scuba diving was something that had to become second nature for us to conduct the underwater experiment as well as we did.

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