Vacuum Power

Materials: ★★★ Requires materials not commonly found in school laboratories
Difficulty: ★★☆ Can be done by science teachers
Safety: ★★☆ Some safety precautions required to perform safely

Categories: Force, Pressure and Fluids

Alternative titles: Vacuum Suction Board, Air Pressure Lifting Demonstration

Summary

By attaching a vacuum cleaner to a plywood board with weatherstripping, the suction creates a strong seal against a flat surface. The reduced air pressure between the board and the surface allows normal atmospheric pressure to hold the board firmly in place, demonstrating how pressure and surface area combine to create strong lifting forces.

Procedure

Measure the diameter of your vacuum’s tube attachment.
Drill a hole of matching diameter in the center of a 3' x 4' plywood board.
Attach weatherstripping around the perimeter of one side of the board to help form a tight seal.
Thread rope through drilled holes to create two handles on the board.
Insert the vacuum tube into the central hole and seal it with hot glue or additional weatherstripping.
Turn on the vacuum and press the board against a smooth, flat surface such as a wall, ceiling, refrigerator, or whiteboard.
Test the strength of the suction by pulling gently on the board or even using the straps to support weight.

Links

📄 Vacuum Power! (on page 60) - Aaron Adamson: https://www.unco.edu/nhs/science/pdf/demos/2011_CSC_demos.pdf

Variations

Try different board sizes to see how surface area affects suction strength.
Use different types of vacuums (handheld, upright, shop vac) to compare performance.
Experiment with sealing methods to test how airtightness affects suction.
Test on different smooth surfaces (glass, metal, painted wall).

Safety Precautions

Ensure the board is properly sealed and stable before attempting to hang weight.
Do not hang full body weight unless absolutely certain of the vacuum’s strength and the board’s stability.
Keep fingers away from the vacuum inlet when in use.
Avoid testing on fragile or easily damaged surfaces.
Always supervise children during the demonstration.

Questions to Consider

Why does increasing the surface area make the suction effect so much stronger?
How does atmospheric pressure contribute to holding the board in place?
What happens if the seal is imperfect and air leaks into the system?
How does this relate to real-world suction devices, like suction cups or industrial lifting equipment?
Could this principle be scaled up for heavy lifting in construction or engineering?