|Alisdair banging his own "drum" . . .|
Mahaney says, "When an object vibrates, it moves the air around it. You can hear and feel vibrations. You can't see vibrations in the air, but you can see and hear things they have an effect on, like a guitar string" (Pages 20 and 21).
To do this experiment we needed:
a sheet of plastic wrap or cling film
an elastic band
some rice (we used an Uncle Ben's flavoured mix!)
a flat metal pan (we used a 9 x 13 cake tin)
Here are Mahaney's instructions:
"STEP 1 - Pull a sheet of plastic wrap tightly over a cake pan or a large plastic bowl. Use a large rubber band to hold the plastic in place. You've made a drum.
STEP 2 - Sprinkle a spoonful of rice on top of the plastic.
STEP 3 - Hold a flat metal pan a little above your "drum" and tap the flat metal pan with a wooden spoon or a ruler. When you tap the pan, the metal vibrates. The vibrations move the air around the tray. When these vibrations reach the plastic, the plastic vibrates, too. When this happens, the rice moves!"
|Our "drum" . . .|
|Drum with rice on top . . .|
|Our "drum" and the cake tin . . .|
|Alisdair enjoying eating his snack!|