Mind Body Soul Summer: Float Your Boat

Build a tin foil boat and test out your design by seeing how many pennies the boat can hold without sinking.



  1. Get your supplies. You will need some 6-inch squares of tin foil, a handful of pennies, and a container or dish pan half-filled with water.  
  2. Construct your boat by bending and folding the tinfoil. Predict how many pennies you think your original design can hold without sinking.  
  3. Put your boat in the container of water and add pennies one by one until the boat sinks. Take the boat out of the water and count how many pennies the boat was holding. Remember not to include the penny that sank the boat!
  4. Think you can make improvements? Construct more boats and try out different designs. Learn what works and what doesn’t work after each attempt. Consider factors such as the height and thickness of the sides of the boat, the size of the bottom of the boat, and where you place the pennies within the boat. 


THINGS TO CONSIDER:                                                                                                                                                         

When a boat floats, it must push water aside to make room for itself. The water also pushes back on the sides and bottom of the boat; this force is called buoyancy. Buoyancy is what keeps the boat floating.  The more water the boat pushes aside due to size and shape, the more force the water uses to push back and support the boat in the water. For this reason, the size and shape of your tin foil boat design determines how many pennies the boat can hold without sinking.     



See how many pennies an even bigger tin foil boat can hold. What happens if you use 12-inch squares of tinfoil to design your boat instead of 6-inch squares? See if the water affects your results. Try floating your boat in “saltwater” (similar to ocean water) by adding salt to your container of water.

Thanks to our sponsor, National Grid.

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