Design a Boat

Challenge Question

How can we design a boat using recycled materials that can hold at least 15 pennies and float for at least one minute?


(Use anything you have around the house, but here are some options to consider)

  • Paper
  • paper towel rolls
  • rubber bands
  • plastic plates
  • plastic cups
  • pennies (15 or more)
  • aluminum foil
  • plastic wrap
  • recyclables
  • tape
  • popsicle sticks
  • string
  • balloons
  • legos



  1. Begin with a simple sink or float test by placing materials in a bin of water and seeing if they float. Some materials you might want to test include: paper, clay, marble, paper clip, piece of wood, penny, etc. Make a prediction for each object first.
  2. Once you’ve completed testing your materials, begin building.
  3. When you have a completed boat, place it in the bin and see if it floats (with no weight)
  4. If your boat floats without weight, begin adding pennies onto it and see how many it can hold.
  5. Notice what works and what doesn’t work and modify/recreate your design as needed.


buoyancy: a force that causes an object to float

volume: the amount of space an object takes up

stability: the ability to recover equilibrium

center of gravity: the point of an object where if all the mass were concentrated on that point, the object would remain in equilibrium

equilibrium: the state of an object being at rest where the net forces acting on it are zero



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