Ketchum Middle School

The sixth grade scientists created a physical model to explain how differences in air pressure form wind. Students used a bottle with a small hole in it, a pump cap, and marshmallows to demonstrate a change in the bottle. They learned that density increases if particles of a material are packed closely. Inside the bottle, the high density of air particles caused an area of high pressure. Because cold air is denser and heavier than surrounding air, cold air will sink. When cold air reaches the ground, the air spreads out horizontally. This horizontal movement of air is commonly called wind.