(Last Update: 16:01 PDT 8 April 2007 )

Notes for Family Science Night: Al-foil boats

Kevin Karplus

I found a description of the basic idea at http://pbskids.org/fetch/parentsteachers/activities/pdf/FETCH_FloatMyBoat_Notes.pdf, but I did a little experimenting on my own to see what was needed. Since this station involves water play, I expect it to be quite popular, and so we need enough copies of the materials and instructions for several kids (or parents) to play at once.

Materials List

• 6"x6" squares of aluminum foil, for making boats. A 75'x1' roll of aluminum foil should be make 300 squares, which should be about the right number, assuming that 50 people try to make an average of 6 boats each. These should be pre-cut before the event.

  I considered using 12"x12" sheets of aluminum foil, but even a very crude design (a simple rectangular tray) could support over 200 pennies, which would get tedious to count. Given foot-wide aluminum foil rolls, 6"x6" (as suggested at the pbskids.org site) seems most appropriate.

• Pennies to use as weights. A simple boat can support 20-30 pennies before it sinks. We'll need around 300-400 pennies.
• One under-bed storage container, half full of water, for testing boats.

  The biggest problem here will be filling and draining the container. The water will be 40x105x10cm, so 42 liters (weighing about 93 lbs). We could fill it with a hose, or with bottles. Draining it will probably require having several people lifting the container at once, since it is probably not strong enough to be lifted from just the two ends when full of water.

• Gallon bottles for transferring water to the container.
• Towels for people to dry their hands after doing the experiment.
• A colander and dish-washing tub for draining pennies that have sunk boats.
• Laminated instruction sheets saying something like:
  • The goal is to use one 6"x6" square of aluminum foil to make a boat that floats and can carry a cargo of pennies.
  • See how many pennies your boat can carry before it sinks.
  • Record the results on the poster.
• A large laminated poster with columns for name and number of pennies floated.
• A grease pencil (and spares?) for writing names on the poster.
• A sign for the station: "Float your Boat"