======Van de Graaff Pie Tins======


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**Alternative titles:** Floating Pie Plates, Van de Graaff Coulomb Repulsion
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====Summary====                   
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====Procedure====  
  - Place the Van de Graaff generator in an open space with enough room above for the plates to fly off.  
  - Plug in the generator and grounding rod.  
  - Stack 5 or more small aluminum pie plates upside down on the dome of the generator.  
  - Use the grounding rod to switch on the generator and step back.  
  - Watch as the plates charge, repel each other, and fly off one by one.  
  - When all plates have discharged, use the grounding rod to safely turn off and discharge the generator.  




====Links==== 
Why Do Pie Plates Fly Off a Van de Graaff Generator? (Physics Demo) - Phantastic Physics: 
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📄 Putting Pie Plates on a Van De Graaff Generator - Classroom Physics Demos: [[https://demos.smu.ca/demos/e-n-m/53-pie-plates]]\\


====Variations====
  * Use different sizes of pie plates to compare how mass affects the speed and height of lift-off.  
  * Try lightweight foil trays or other conductive objects.  
  * Place a lightweight toy (like a rubber duck) on top of the plates for added visual effect.  
  * Record in slow motion to observe the instant each plate becomes charged and separates.



====Safety Precautions====
  * Always use the grounding rod to switch the generator on and off.  
  * Discharge the dome after use with the grounding rod.  
  * Stand back while plates are flying to avoid accidental hits.  
  * Do not operate near sensitive electronic devices.




====Questions to Consider====
  * Why do the pie plates repel each other instead of staying stacked?  
  * What role does conduction play in transferring charge from the dome to the plates?  
  * Why do lighter plates fly off more easily than heavier ones?  
  * How does this demonstration model the way charge distributes itself on conductors?  
  * In what ways is this similar to the sparks and hair-raising Van de Graaff demonstrations?