Summer Fun with Bouncy Balls!

What better way to have some summer fun than playing with polymers and making our very own BOUNCY BALLS! That’s right. With a few easy to find ingredients, our scientists were able to create their very own bouncy balls. Now, our bouncy balls didn’t have quite the “spunk” of the classic bouncy balls you find in any number of stores – those balls are created under 50,000 pounds of compressed energy! We certainly have some muscles, but not enough to compress the materials that much. Nonetheless, our creations were pretty cool.

bouncy ballPerhaps the first and most famous bouncy ball was the Super Ball created by Wham-O (the company also responsible for frisbees, the Slip ‘n Slide, etc.). Here are some interesting facts and trivia about that classic toy, as noted on cracked.com:

  • The bouncy ball was invented in 1965 by Norman H. Stingley and sold as the Super Ball by Wham-O
  • They come in all shapes, sizes, and colors (even square!)
  • The average bouncy ball can retain up to 70% of its kinetic energy when thrown at a hard surface (Remember – potential energy is “stored” energy, and kinetic energy is “active” or “released” energy. Retaining that much kinetic energy is why bouncy balls seem to bounce on and on and on…)
  • An average adult can slam a Super Ball down hard enough for the bounce to clear a three-story building!
  • The spin of a Super Ball reverses on each bounce
  • As a promotional stunt, Wham-O made a Super Ball the size of a bowling ball and dropped it off the roof of a 23-story hotel, just to see what would happen. On the second bounce, it destroyed a parked car!

I thought it would be fun to compare 3 varieties of bouncy balls:  1) A recipe that allowed us to create a bouncy ball completely from scratch; 2) a store-bought kit that provided us with some fancy polymers and molds to create colorful balls; and 3) a simple store-bought, already made bouncy ball.

We started by making a ball completely from scratch, using the recipe below shared on KidsActivitiesBlog.com:

  • 1 tablespoon of glue (best to use multipurpose vs. washable)
  • 1 and 1/2 teaspoons of corn starch
  • 2 tablespoons water (best if water is warm)
  • 1/2 teaspoon of Borax (a powdered detergent that can be found in the laundry aisle of most supermarkets)
  • food coloring (optional)

The key to this experiment is combining the ingredients in the right order, and in the correct ratios. First you want to pour your water and borax into a cup to combine and dissolve the Borax powder. Next, in a separate cup, you should mix the corn starch and glue together (the consistency may start out a little dry, but keep stirring until you have a smooth, liquid-like consistency – like melted frosting). If you choose to add a few drops of food coloring, the time to add it is after you have mixed the glue and corn starch together (before you combine all materials together. Now, pour the Borax/water mixture into the cup with the glue/corn starch mixture. IMPORTANT! BE SURE TO LET THE COMBINED INGREDIENTS SIT STILL WITHOUT MIXING FOR 20 SECONDS! This gives the ingredients a chance to begin reacting with each other; in other words, the polymer chains get busy linking together. After 20 seconds, begin stirring. Just as our scientists discovered, you’ll see that the mixture quickly solidifies and becomes difficult to stir (NOTE: Not all of the liquid will mix in – there will be some left over). Now pull that solid blob out of your cup, and begin to squeeze it, and roll it, and mush it into the best ball shape you can…and give it a test bounce!

bouncy ballFor our second test, we used a kit purchased from a wonderful store online – Educational Innovations.  The kit provided us with polymer crystals of various colors and the molds to actually create the balls. The instructions were very straight-forward. Our scientists combined a variety of colors to make make rainbow-swirled balls. The only extra materials I needed to provide were cups filled with water to dunk the molds into, and a stop watch to time our progress at various stages. [It only takes a few minutes here and there.] The end result is a product very similar to a store-bought bouncy ball. The bounce was definitely higher and more consistent than our ‘from scratch’ recipe. However, both of the balls created with method #1 and method #2 NEED TO BE STORED IN A SEALED BAG FOR PRESERVATION. Neither of the balls will last forever, though the ball created from the kit will definitely have a longer shelf-life, even with both balls sealed in bags.

In the final minutes of the program, I distributed some store-bought bouncy balls so our scientists could compare their results with a factory-produced ball.