Water Balloon Toss 2.0

Challenge
One activity my family and I just did this summer was a water balloon toss! We filled many balloons with water, but all the balloons had different amounts in them. We weren't being scientific at the time because our main goal was fun. But during the toss competition, I started noticing some differences. Some water balloons broke very easily when tossing back and forth. Other water balloons bounced off hands and off of concrete like bouncy balls! How could this be? What was the difference? This made me think of this month's STEM Challenge. Your challenge is to construct the best device for catching a water balloon without it breaking during a water balloon toss. What will be the best material to use? Are there items already designed or things from nature you could replicate? How far will your design last?

Your water balloon catcher does have some criteria and constraints. The water balloon being tested should be about the same size for all designs. The same distance should be used when tossing back and forth to the water balloon catcher. 

Materials

• water balloons
• netting
• assorted plastic bags
• other balloons
• cardboard pieces
•  assorted fabrics (old shirts)
• cotton balls/stuffing
• rubber bands
• tape
• string/yarn
• paper

Hints and Tip for Success

1. Allow students planning and discussion time by having them experiment with the items to see how flexible, movable, heavy they are, and how they might be used to create a catcher.
2. After experimenting, allow student groups to plan their design. Include as many ways to improve their catchers as needed.
3. For differentiation, adjust the amount of materials available and allowed to use, add any additional materials, increase or decrease the water in the balloon being tossed, give specific dimensions the catcher must be. Adjustments could be made to make it more challenging or simpler.
4. Determine a process for tossing the water balloon to the catcher for all groups so it is consistent,  what to do if their catcher works (greatest distance it will work), and agree on how the balloon will be tossed (overhand, underhand, lots of arc, little arc).
5. Discuss properties of each material and ask students to think about the properties of a water balloon (what makes it break easily or bounce? does the color of the balloon change these properties?)
6. Connect to engineering by discussing properties of materials, designing any type of container for holding water, or developing ways to transport fragile items safely.
7. Connect to ELA by reading Balloon Trees by Danna Smith, where it takes the reader through the journey oh how a balloon starts as a tree to its completion.  A fiction book is Harvey Potter's Balloon Farm by Jerdine Nolen that explores how a farmer grows balloons.