======Center of Gravity======


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**Materials: **{{$demo.materials_description}}\\
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**Safety: **{{$demo.safety_description}}\\
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**Categories:** {{$demo.categories}}
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**Alternative titles:** Center of Mass
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====Summary====                   
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====Procedure====  
  - Cut out an irregular shape from plywood or stiff cardboard.  
  - Drill three small holes near the edges of the shape.  
  - Hang the object from one of the holes using a string or hook.  
  - Use a plumb line to draw a straight vertical line downward from the point of suspension.  
  - Repeat this process from at least one other hole, drawing another plumb line.  
  - Mark the point where the plumb lines intersect—this is the center of gravity of the object.  
  - On the reverse side, mark the center of gravity with a colored dot, along with several other arbitrary points.  
  - Throw the object with a spinning motion and observe the dots. All dots blur, but the center of gravity dot follows a simpler path, showing why it is often used to describe motion.



====Links==== 
Centre Of Gravity - Defintion, Examples, Experiment - Educational Videos: 
{{youtube>R8wKV0UQtlo?}}\\

📄 Center of Gravity - UNCO: [[https://www.unco.edu/nhs/science/pdf/demos/2001_CSC.PDF]]\\
🎞️ MIT Physics Demo - Center of Mass Trajectory - Mittechtv: [[https://www.youtube.com/watch?v=DY3LYQv22qY]]


====Variations====
  * Try different irregular shapes to compare how the center of gravity is located.  
  * Use transparent plastic instead of wood, so students can see the plumb lines directly.  
  * Hang the object from three or more points to confirm the accuracy of the center of gravity location.



====Safety Precautions====
  * Ensure objects are thrown in a safe, open space away from people or breakable items.




====Questions to Consider====
  * Why must the center of gravity be above the support base for an object to remain balanced?  
  * Why do the plumb lines always cross at the same point, regardless of where the object is hung?  
  * Why does the dot at the center of gravity appear steady while other dots blur when the object spins?  
  * How could this method of finding the center of gravity be useful in real-world applications?