Little Shop of Physics
Science Activity Kits
This one takes some practice to get it right. First, poke a small hole In the bottom of the cup. Now tie small knot right at the end of your plastic strip, and push the other end of the strip through the bottom of the cup, and pull the strip through so that the knot is against the bottom of the cup, as at right. Now gently pinch the strip, and push your fingernail against it. Rub your fingernail down against the length of the strip... what happens? It should say "Science is fun!"
This does take practice! Be patient -and be gentle!!!
What Is Going On
When you rub your fingernail against the plastic strip, it rides
over a series of ridges in the strip. This makes the strip vibrate. And the ridges are made just right so that the vibration makes a particular sound -the speech that you hear. The point of the cup is to the amplify this sound so that you can hear it.
Other Things to Try
The talking strips can also make a balloon talk (hold the end of the strip against the balloon) or a box. Also, you can use something other than your fingernail -how about a penny?
The talking strips are perfectly safe -but they are fragile! If you pinch them too hard, they will break.
The text above is from a handout
provided by the Little Shop of Physics.
Where to get them
Steve Spangler Science