baking soda submarine

BAKING SODA SUBMARINE
Tools:
Paring knife
flat bladed screwdriver (blade should be a little wider than a pencil)
pencil
big bowl of water
Supplies:
carrot (ready-to-eat baby carrot type)
several toothpicks
baking powder (not baking soda)

Step 1

Gather your supplies.
Step 2

Cut the carrot in half lengthwise and trim off the ends.
Step 3

Drill a hole allmost all the way through the carrot (from the flat side).
Step 4

Break toothpicks in half and insert as shown.

Here is the bottom of the sub. Observe the hole.
Step 5

The sub should just barely sink. Add or remove toothpicks till it barely sinks to the bottom.
Step 6

Fill the hole with baking powder.
Step 7

Pack the hole full and tight with the pencil.
Ready for launch!
Step 8

Place the sub in a bowl of room temperature water and watch it dive, surface and dive again!

Click here a for a video of this project (external link)


The Science Behind It:The carrot submarine is initially denser than the water. When the submarine enters the water, the baking powder starts to react and carbon dioxide gas is produced. The small bubbles of gas get caught on the flat surface, making the submarine less dense than the water and causing the carrot to rise to the surface. The bubbles will then release from the carrot causing it to dive to the bottom again. The submarine will continue this pattern until all the baking powder is gone.
Check out the video: www.metacafe.com/watch/805804/baking_powder_submarine/
www.coolscience.tripod.com