SaH: Polar Bear Play

In this STEM Challenge, you will build a floating “iceberg”.  


How can you create an “iceberg” that floats because it is less dense than the water it is in?  How many polar bears will fit on your “iceberg” and still float?

Some suggested materials

  • aluminum foil
  • gummy bears (or any small item that represents “polar bears”
  • wax paper
  • straws
  • tape
  • bucket of water


What to Do

  1. Take time to brainstorm your design.  Write down some notes or draw a picture.
  2. Create your design using the materials. 
  3. Test out your design by floating your “iceberg” in the bucket of water. Does it float?  
  4. Add one gummy bear at a time.  How many can you add before any fall off or your “iceberg” or your “iceberg” sinks.

What is Happening?

Density plays a huge role in the floating of icebergs. First of all, frozen water is less dense than the same amount of unfrozen water. Think about it, ice cubes float in our glasses of water. Secondly, fresh water is less dense than salt water.  Icebergs are made up of frozen fresh water.  Lastly, icebergs contain a great deal of air bubbles. Air is less dense than water.  The trapped air within the iceberg helps it float.  


Activity add-ons:

Are there other materials you can think of that would add to the success of your “iceberg”? What are they?  How would you add them to your design? Would these additions help your “iceberg” be less dense than the water it is in?  What happens if you add salt to the water?  (Check with an adult, you may need a large amount of salt to create salt water)

Share this post!

Join Our Mailing List

Stay up to date on news and events by the Reading Science Center.