======Bernoulli’s Toilet Paper======


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**Materials: **{{$demo.materials_description}}\\
**Difficulty: **{{$demo.difficulty_description}}\\
**Safety: **{{$demo.safety_description}}\\
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**Categories:** {{$demo.categories}}
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**Alternative titles:** Leaf Blower Bernoulli Experiment
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====Summary====                   
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====Procedure====  
  - Hold a toilet paper roll horizontally on a stick.  
  - Blow steadily across the top of the roll. Observe how the paper lifts slightly.  
  - Repeat the experiment using a leaf blower directed across the top of the roll.  
  - Watch as the toilet paper unrolls and flies upward, high enough to resemble toilet papering a tree.  




====Links==== 
Bernoulli's Principle Demonstration: Toilet Paper - SDPB: 
{{youtube>025lsG3VHKM?}}\\

Leaf Blower Toilet Paper Fun! Bernoulli's Principle | Mister C TV - learningscienceisfun: 
{{youtube>BxIhP3WSQ7Q?}}\\

📄 Physics Force - University of Minnesota: [[https://physicsforce.umn.edu/content/toilet-paper-tree-0]]\\


====Variations====
  * Try using different air sources (hair dryer, fan, compressed air) to compare effects.  
  * Test with lighter or heavier paper products (tissue paper vs. paper towels).



====Safety Precautions====
  * Keep a safe distance when using a leaf blower.  
  * Do not aim the blower at people or fragile objects.  
  * Pick up toilet paper afterward to avoid littering or creating slipping hazards.  
  * Use protective eyewear if working close to high-speed air streams.




====Questions to Consider====
  * Why does blowing across the paper cause it to rise? (The faster-moving air above reduces pressure, so higher pressure below pushes the paper up.)  
  * Why is the leaf blower more effective than just blowing with your mouth? (It produces a much faster airflow, creating a stronger pressure difference.)  
  * How does this relate to airplane wings? (Air travels faster over the curved top surface of a wing, lowering pressure and creating lift.)  
  * Can Bernoulli’s principle alone explain all lift? (Not entirely—other factors like circulation and angle of attack also play roles in real aerodynamics.)