Physics Exercises/Equilibria


 * 1) [[image:Stacked-half-balls.jpg|thumb|110px|Stacked half-balls]] How many half-balls can be placed on top of each other? The picture shows three. Can you add one more?
 * 2) What shape take 2 equal soap bubbles when they touch each other? What happens when the bubbles have different volumes?
 * 3) A foil balloon is made of 2 disks of thin, unstretchable, nylon film welded at the edge. What shape takes the inflated balloon?