Keeping Afloat - Oh Buoy!

Challenge
Did you know early sailors used to wear life jackets made from cork? In later years, they started using a vegetable silk instead! The vegetable silk, kapok, is very similar to cotton. It became the standard for making life jackets. Then, due to war, the military developed an inflatable type of life jacket. The inflatable life jackets are still used today. Eventually, kapok was replaced by technological means when synthetic foam was created. This new means of design allowed the life jackets to be more flexible and the designers to create a variation of life jackets that we currently see today.
 
With the weather getting nicer, swimming will become more prevalent and little children need to stay safe around the water. Life jackets are the easiest way to do this! For some reason, all the life jackets have disappeared at the community pool. The lifeguard won’t let you OR your baby sibling in unless you both have life jackets. Well, why not design your own? Your challenge is to create a prototype life jacket out of the provided materials to help a plastic doll float.
 
Your design does have some criteria and constraints. The life jacket can only be made using the foam pieces and rubber bands. The life jacket should resemble more of a life jacket than a boat object. Finally, and most importantly, however the plastic doll is dropped in the water with its life jacket (head first, feet first, on its side, etc), the doll’s face must return to the top of the water and be sticking out in order to breathe! No doll’s face should be submerged in the water in any way.

Materials

• small plastic dolls (mini plastic baby favors used for Baby Showers work well)
• foam pieces (foam pipe insulation works well)
• rubber bands (any size)
• scissors
• plastic containers
• water

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Hints and Tips for Success

1. Allow students planning and discussion time by having them experiment with sample materials to see how they react with water (sink or float).
2. After experimenting, allow student groups to plan their final design.
3. Groups only need a small amount of foam and rubber bands to use. The foam can be cut in any way.
4. For differentiation, limit or increase the amount of foam or rubber bands students get, adjust the criteria to how the baby has to float, take away one of the materials, or show examples of baby life jackets.
5. Allow each group to have its own plastic container filled with water to conduct their experiment.
6. Students will probably struggle at first but persistence is key with this challenge. There are actually many different solutions.
7. Connect to science and mathematics by having students figure out density of the materials, displacement, and/or buoyancy.