Monday, April 11, 2011

How much does a cloud weigh?

It depends on the amount of moisture is in the cloud and the size of the cloud. Different kinds of clouds carry different amounts of weights.

"Cloud" Experiment #1- What Happened?

We made a cloud using boiling water in a jar, adding a lit match, then by putting a cup of ice on top enclosing the jar. The ice cools the air at the top of the bottle. When the water vapor rising from the hot water on the bottom of the bottle reaches the cooler air at the top, it begins to condense and form drops around the smoke particles, which serve as condensation nuclei, and a cloud is created.

"Cloud" Experiment #2-What Happened?

We made a cloud using a plastic bottle with a small amount of water in it, then lit a match put it in the bottle, & then quickly closed the bottle. When we squeezed the bottle we increased the pressure in the bottle, creating a cloud. (Clouds need three things to form: Moisture, a temp/ pressure change and a condensation nuclei.)

Wednesday, April 6, 2011

Air pressure effects on a can

The soda can crumpled in on itself. When you heat it up, it causes the air temperature & pressure inside the can to rise.  When the air inside the can was put into the cool ice bucket, the air cooled and caused the pressure inside the can to decrease. As the pressure on the inside walls of the can decreased, the walls of the can collapsed since there wasn't enough air pressure inside the can to offset the air pressure on the outside of the can.

For the Egg Activity you need: a shelled hard-boiled egg, an empty glass frappucino bottle, a peice of paper and a match.

I predict that the egg is going to be sucked into the bottle.

What actually happened: I was right.When we lit a fire in the bottle, the air in the bottle became much warmer. The air expanded as it got warmer and warmer and it was crowded in there for the air. Then the flame burns out. As the air inside the bottle began to cool off, it also shrank in size again. The air pressure inside of the bottle was reduced. So, the air pressure outside of the bottle and on top of the egg was greater than the air pressure inside the bottle. The air pressure from outside the bottle pressed and pushed the egg down the bottle.

When we got egg back out again: When we blew and forced air back into the bottle, we increased the air pressure inside the bottle. So, the air was pushing and shoving the egg to get out of the bottle. We saw just the opposite thing happen with air pressure when we made the egg drop into the bottle. When there is air pressure, the air is shoving and pushing things around and in it.