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.)