Straw Through a Potato

Materials: ★☆☆ Easy to get from supermarket or hardware store
Difficulty: ★☆☆ Can be easily done by most teenagers
Safety: ★☆☆ Minimal safety procedures required

Categories: Pressure and Fluids, Simple Machines

Alternative titles: Straw and Potato Trick

Summary

A straw normally bends when you try to push it into a potato. But if you cover the top of the straw with your thumb, air trapped inside makes the straw strong enough to pierce through the potato.

Procedure

Hold a potato in one hand.
Try to push a straw straight into it - notice the straw bends.
Now place your thumb over the open end of the straw.
Push again—the straw goes into the potato without bending.

Links

Straw Through A Potato Experiment - Da Vinci Kids:

How to Put a Straw Through a Potato - Cool Science Experiments Headquarters:

📄 Straw Potato - KiwiCo: https://www.kiwico.com/diy/stem/quick-easy-experiments/straw-potato?srsltid=AfmBOopZ-ci_tuduEA3cUKsTKP_SxCHrJ8s9ZgRH_MgSnFxrDTCRil7p

Variations

Try with paper straws vs plastic straws.
Test what happens with half-full vs fully covered straws.

Safety Precautions

Keep fingers away from where the straw enters the potato to avoid pokes.
Push firmly but not with excessive force.
Supervise children to prevent accidents.

Questions to Consider

Why does covering the top make the straw stronger? (Air trapped inside is compressed, pushing outwards and stiffening the straw.)
What type of pressure is being demonstrated? (Air pressure from trapped gas molecules.)
How is this similar to how air supports objects like tires or balls? (The air inside presses outward, making flexible materials rigid and strong.)