Activity: Air Pressure

• Print

Objective

• To show that air has pressure

Materials

• Water glass
• Pieces of thin flat cardboard

Procedure

• Fill the glass to the top with water.
• Place the cardboard over the glass.
• Holding cardboard tightly to the glass, carefully turn the glass upside down.
• Remove your hand from the cardboard.
• Hold cardboard in place against the glass.
• Tilt the glass or hold it sideways and the cardboard still remains in place.

Observations

• The water will leak out if the cardboard is not held tightly when turning the glass over.
• The cardboard sticks to the glass as it is turned.

Questions

• Did the water leak Out? Why? (The water leaked out because it was not held tight enough next to the cardboard.)
• What could you do to keep the cardboard dry longer? (Use thicker cardboard, answers will vary.)
• Did the cardboard stick when the glass was turned sideways? Why? (Yes, the pressure of the air next to the cardboard caused it to hold tight.)

Conclusion

• The air pressure kept the water from falling out of the cardboard covered glass.