We did our first Friday fun yesterday afternoon. We were supposed to make homemade bouncy balls...except they didn't quite turn out right. Have you ever done a science project like that? Something tells me I'm not alone. At any rate, we had a great time! We used Time's Big Book of How for the instructions. In general, I really like this book. I can't say if it was us or the book that caused our fail, but the book does give a great explanation for why balls bounce.
Essentially, when a ball is dropped it using kinetic energy(energy of motion). When it hits the ground it stops momentarily, flattening the ball, and then the stored up energy is release back to the ball as kinetic energy causing it to bounce. The book goes into more detail.
We ended up with some slime or goop that the kids thought was very fun. It would squish together into a solid and then when released on the table it would turn back into a runny puddle. I'll have to admit it was a pretty neat sensory experience.
Here's how we did it...
Mix 4 ounces of school glue (we used Elmer's Glue All and that may have been our downfall...we'll have to try with school glue and report back!) with 4 ounces of distilled water. Add 10 drops of food coloring (we used red and blue to make purple). Mix together. In a separate bowl, mix 1 cup of distilled water with 1 teaspoon of Borax powder until it is dissolved. Then, slowly add the glue mixture to the Borax mixture and stir. Pour the mixture onto a protected surface and knead until it's smooth. Then play!
I did a quick search to see if anyone else had made bouncy balls and found that Mom to 2 Posh Lil Diva's had success during their mad science week. Maybe we'll try again using their recipe!