Vibrating Coins (Funky Physics Experiments)

You will need:

1. Water
2. Coin
3. Empty plastic bottle with
   a narrow mouth
4. Refrigerator

Understand the science behind the
temperature of gas and the speed of molecules
by conducting this simple experiment with
your everyday household items.

INSTRUCTIONS

1. Take an empty plastic bottle and place it in the refrigerator to cool down.
2. Leave it inside the refrigerator for half an hour at least.
3. Remove the bottle, dip you finger in normal water and dab a few drops of it onto the mouth of the bottle and on the edges of the coin.
4. This will help seal the bottle.
5. Place the coin on the mouth of the bottle. (It should not fall through)
6. Place your hands on the side of the chilled empty bottle firmly.

RESULT

The coin on the mouth of the bottle begins to vibrate. This takes place because of the air inside the bottle. As soon as the bottle is removed from the refrigerator, the air temperature inside the bottle begins to rise. As a result, the molecules of air begin to expand and move at a faster rate. Since the coin seals the bottle, the molecules hit the coin with greater force with the rise in air temperature inside the bottle, in order to escape, making it vibrate.