Caroline Imreibe

Anti-Gravity

Concept: Gas Pressure. Overcoming the forces of gravity, with the use of liquids and pressure.

Materials: one 50 mL-graduated cylinder

one clear straw

Red or blue food coloring

Small piece of clay

Directions:

1. Press the clay against the bottom of the beaker.
2. Fill the jar one half full with water.
3. Add four drops of food coloring to water and stir.
4. Slowly lower straw into colored water and stand vertically, pressing it into the clay.
5. Quickly turn the beaker upside down in sink or bucket. Have the students observe that there is still liquid in the straw even though it is upside down.
6. Turn beaker right side up and set it on table. Notice the liquid level inside the straw.

Introduction: It's a known fact, what goes up must come. (Dump colored water out) DOWN!

Explanation: The colored water in the straw remains even though the beaker is empty and held upside down. This happens because the air from the outside in the straw pushes up on the water when the beaker is emptied out.

The straw is stuck in some clay on the bottom of the beaker. The clay blocks the atmospheric pressure from pushing the water down and out of the straw. When the beaker is upside down,this air pressure against the water in the straw is greater that the force of gravity, hence the idea of antigravity..

Safety: Handle wet glassware with care.

Waste Disposal: Empty water into sink.

Reference: Unknown