Metal sinks, so why do boats float?
Discover the magic of buoyancy using a few very simple materials. The concept of buoyancy and water displacement can be very complicated, but the idea that heavy objects can be molded to float is a simple one.
Buoyancy: An upward force exerted by a fluid that opposes an immersed object. If the object is heavier then the upward force, the object sinks, if the upward force is stronger, the object floats.
Materials: Tinfoil, a bowl of water, beans (you can also use coins, marbles, or any other uniform object) random boat making materials (toothpicks, clay bits, paper, etc).
Start by throwing a metal coin in the bowl of water to show that metal sinks, then ask the question: If you make a boat using metal (tinfoil) how many beans can it hold before sinking?
Hadley and Finley both made their boats using only tinfoil to start with, and after a few minutes were able to keep their boat afloat with beans inside. After a few tries they started including some of the other materials into their designs, and ultimately ended by dumping everything in the bowls and making some sort of soup. They were very curious about what floats and what sinks.
The best part of this challenge was that after we were done, many of the beans were used outside and ended up in the grass, and a few days later little seedlings are emerging (who knew store bought, very old beans would grow!)
Please feel free to share your own version of this challenge either in the comments or the linky list below!
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