If you're on Pinterest, chances are good you've seen this activity. But for the few who haven't, get ready for some seriously cheap science fun. We made a hovercraft!
An old CD that you no longer need
Glue gun and glue sticks
soda bottle screw top (you want one that's fairly deep)
latex party balloon
Poke several holes in the plastic bottle top with the thumbtack.
Use a hot glue gun (Adults, please. No children. Those things are H-O-T) to apply a bead of glue to the edge of the bottle top and glue it to the center of the CD, over the hole. If necessary, apply a bead of glue around the cap to make sure it's totally secure.
You're almost done.
Now blow up the balloon. Twist the neck of the balloon to keep it inflated and pull the lip of the balloon over the edges of the bottle cap.
Ask your child to make predictions. Before we released the hovercraft, my son thought it would glide through the air more like a hot air balloon.
Let it Go
Set on a flat surface like a countertop or wood floor. Release the balloon and watch it glide along without any effort just over the surface.
Invite the child to form a hypothesis about why and how this works.
How it WorksThe force of the air that exits the balloon as it deflates goes through the holes in the bottle cap, pushes against the surface (floor or counter), and creates a cushion of air over which the CD glides freely.