Hovercraft

Another cool science experiment/activity you can do with your kids is build a simple hovercraft.  You need an old CD or DVD, the cap of a sports bottle that pops up and down, a balloon, and superglue.  Glue the cap on the center of the CD/DVD.  Blow up a balloon and attach it to the closed cap.  Pop the cap open and you've created a simple hovercraft.  The CD/DVD won't rise above the table top, but a cushion of air between the disk and the table removes friction, allowing the disk to slide around.

My daughter and I did this yesterday and our first attempt (not recorded unfortunately) was very successful.  The CD flew across the table very quickly.  The second attempt, which I recorded, shows a bit of hovercraft action, but not nearly as much as the first attempt.  See below.

We set out to do this a third time and get a successful attempt on video, but while attaching the balloon to the cap, I broke the cap.  This was the only cap in the house, so that was the end of the experiment for the day.  My daughter was a bit sad, but she was glad to see it work the first two times.