On Friday, April 2, 2009, Mrs. Catharine Reavley’s Calculus class were asked to come down to Mrs. Dean’s and Ms. Bair's first grade classes to give a presentation on pressure and how it affects the weather.
The first graders have been learning about the weather and pressure as well as how to predict the weather. Mrs. Reavley’s high school students worked to make barometers, which are instruments used to determine what the weather will be like. Their barometers were a bottle half filled with water with a straw that leads down into the bottle, which is sealed tight. When pressure is added (i.e blowing into the straw), the water leaves the straw. If pressure is taken away (i.e. squeezing the bottle), the water goes up the straw.
The High school students also made a cloud in a bottle. They lit a match and put it in a bottle filled half way with water, then closed it with the cap. After the bottle was squeezed a few times, a cloud would appear, showing how pressure applied can affect the clouds.
For the last demonstration they turned on a lamp and sprinkled baking powder on it. Of course, nothing happened. After the lamp had been on for a while and was hot, they sprinkled a little more powder on it; this time it swirled above the light. This was because of the heat from the lamp moving the warmer air upwards away from the lamp.
In a barometer high air pressure indicates good weather and low pressure bad weather. This is because of the rotational directions of the pressure systems. Low pressure is counter-clockwise, High pressure is clockwise.