EQUIPMENT REQUIRED:
50 ml bottle of water
Tomato ketchup sachet
METHOD:
Find a tomato ketchup sachet that will float in your bottle of water. This is your “diver”. Place the lid on the bottle. Your challenge is to make the diver sink to the bottom of the bottle.
RESULT:
Shaking or tilting the bottle will not work! To make the diver sink you must squeeze the sides of the bottle.
The tomato ketchup sachet floats because it contains air, which keeps it buoyant even though it is totally submerged. When the water bottle is squeezed this compresses the air inside the sachet. This reduces the volume of the sachet and therefore increases its density, so it sinks. Releasing the bottle allows the air to expand again and it will float to the top again. |
