======Balancing a Hammer with a Ruler======


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**Alternative titles:** The Hammer-and-Ruler Trick
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====Summary====                   
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====Procedure====  
  - Wrap two rubber bands around the handle of a hammer near its head to form a loop.  
  - Hook the loop around the end of a ruler.  
  - Place the ruler so that its other end rests on the edge of a horizontal surface (like a table).  
  - Let the hammer hang downward while the handle pushes upward on the ruler.  
  - Observe how the hammer and ruler balance as a system.  
  - For variation, replace the ruler with another hammer and repeat.



====Links==== 
Incredible Gravity Tricks | Hammer Ruler and Balancing Forks - World of Engineering: 
{{youtube>iZM68zMhIBA?}}\\


📄 The hammer-and-ruler trick - MEL Science: [[https://melscience.com/AU-en/articles/hammer-and-ruler-trick/?srsltid=AfmBOooeTEkXtFsKNOyfy3--lAVdjOcoQXUrqQA5ReM7kxyOoff1Yvy6]]\\

====Variations====
  * Try using hammers of different sizes to see how the balance changes.  
  * Experiment with placing the rubber band loop at different points along the handle.  
  * Replace the hammer with another heavy object (e.g., wrench) to test the effect of shape and mass distribution.



====Safety Precautions====
  * Ensure the hammer and ruler are securely placed to prevent falling.  
  * Perform the demonstration over a soft surface to avoid damage if it slips.  
  * Supervise younger children when handling heavy tools.




====Questions to Consider====
  * Why does the hammer-and-ruler system balance? (Because the center of mass lies just below the support point, creating stable equilibrium.)  
  * What happens if the center of mass is above the fulcrum? (The system becomes unstable and topples.)  
  * Why does the structure oscillate when nudged? (Because small deviations shift the center of mass, and gravity restores it toward equilibrium.)