My project consists of a series experiments to determine the effect of air pressure in a given environment at various temperatures. The experiments I chose to conduct are:
1) Heat an ordinary pop can on a hot plate and then putting the can upside down in cold water to see the effect of a fast change in temperature.
2) Partially full milk jug with hot water, put the cap on tightly, and let it sit for one hour to see the effect of a slow change in temperature.
3) Setting a small piece of paper on fire and then putting it inside a plastic bottle. Before the flame goes out, a pealed hard-boiled egg will be placed over the opening.
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4) Put the lid on tightly
5) Wait one hour and record my observations and conclusions.
For the third experiment my procedure is:
1) Get a medium sized bottle.
2) Peel a hard boiled egg.
3) Light a small piece of paper on fire and put it inside the bottle.
4) Before the flame goes out put the pealed egg over the opening of the bottle.
5) Record my observations on a piece of paper.
6) Write my conclusions in my science fair logbook.
02/06/99- I conducted the experiment on the pop can.
After 15 minutes, I turned the can upside down and put it in the cool water. There was a loud popping sound while the can crushed. The can only crushed in the middle. There are some sharp edges where the can did not seem to crush in all the way. The can cooled down a great deal after I put it in the water and it crushed. The can was partially filled with water when I took it out of the water.
I think the can crushed because there was a great difference in air pressure. The air molecules expanded from the heat of the can. The opening at the top of the can allowed the expanding molecules to escape. This kept the inner and outer pressure equal. When the can was put into the water, heat was taken away quickly. This caused the molecules to cool and contract. Because the opening of the can was under water, no air molecules could replace the volume of the expanded molecules. This caused the pressure inside the can to be less than the pressure inside. This caused the can to collapse. The can was partially filled with water because the warm air cooled quickly and shrunk, which created a vacuum that, sucked the water in the can. The can did not crush all the way because the water filled up some of the space in the can. The air contracted when it was cooled so there was less air pressure inside the can, which made it collapse.
I can relate the can to our atmosphere. The heated can had high pressure and the water had low pressure just like a storm caused by high and low pressure systems. The popping sound can be related to thunder. In a real storm instead of the can crushing there would be thunder.
02/06/99-I conducted the air pressure experiment on the milk jug.
Before pouring the hot water into the milk jug it had the shape of an ordinary milk jug at room temperature. After the hot water was pored into the jug, it was difficult to put the lid on because it was extremely hot. After the lid was on the milk jug started to expand right away. After a minute, it began to slow and then began to collapse. Over the next hour the jug slowly collapsed even more. When the hour was up, the jug was collapsed...