PRESENTED BY: Cindy Larson-Miller

BORROWED FROM: Newton's Apple

SUBJECT AREAS: Physical Science, Earth Science

CONCEPTS COVERED: Air pressure, weather phenomena

MATERIALS:

Empty pop bottle

Glass measuring cup with a spout

Colored water

PROCEDURE:

1. Turn the empty pop bottle upside down into the measuring cup containing the colored water. Make sure the bottle fits tight into the cup so that the lip of the bottle does not touch the bottom of the glass.

2. Mark a line on the cup to indicate the water level within the pop bottle.

3. Reexamine the water level as the weather changes.

QUESTIONS:

1. Did the water level change with the changing temperature?

2. What is inside the bottle?

3. What force is acting on the water?

4. What causes the water level in the bottle to rise?

5. Why is dry air heavier than moist air?

RATIONALE:

The amount of air within the bottle is fixed at whatever the atmospheric pressure was on the day you turned the bottle upside down. The pressure on the surface of the water depends on the current air pressure. As the weather becomes drier, the air pressure increases, forcing the water to rise in the bottle.

APPLICATIONS: To be added by user