======Sticky Rice Friction Lift======


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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:** Friction in Packed Rice
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====Summary====                   
{{$demo.summary}}



====Procedure====  
  - Fill a clean container (such as a glass jar or plastic bottle) almost to the top with uncooked long grain rice.  
  - Hold the container firmly with one hand.  
  - Push a blunt-bladed knife or pencil straight down into the rice.  
  - Pull the knife out slightly, then push it back in, repeating the process without fully removing the knife.  
  - Add more rice if the level drops as the grains settle.  
  - Continue inserting and removing the knife until the rice becomes tightly packed and resists movement.  
  - Test if the knife can lift the entire container by pulling upward gently.



====Links==== 
Impossible Rice Lift? - learningscienceisfun: 
{{youtube>q_p4cUYaScc?}}\\

Can you lift a bottle of rice with a PENCIL? 🍚✏️ | Friction experiment | Wonderlab+: 
{{youtube>_xSFunK5I_Q?}}\\

📄 STICKY RICE - BBC one: [[https://downloads.bbc.co.uk/bang/handson/sticky_rice.pdf]]\\


====Variations====
  * Try different types of rice (short grain, sticky rice, basmati) to see which packs most effectively.  
  * Use a narrow-necked plastic bottle and a skewer instead of a jar and knife.  
  * Experiment with other granular materials like sand, lentils, or beans.



====Safety Precautions====
  * Adult supervision required.  
  * Handle the glass jar carefully to avoid breakage.  
  * Use a blunt knife to prevent cuts.  
  * Do not force the knife too hard to avoid injury or breaking the container.




====Questions to Consider====
  * Why does the rice become more compact the more the knife is pushed in and out? (The grains shift into empty spaces, reducing gaps until they are tightly packed.)  
  * What role does friction play in allowing the knife to lift the container? (The compact grains press against the knife blade, creating friction strong enough to support the jar.)  
  * Would this work with liquids instead of rice? (No, liquids cannot be compacted to increase friction in the same way as solid grains.)  
  * How might the size and shape of the grains affect the result? (Smaller or stickier grains may pack more tightly and increase friction faster.)