Today we invite everyone to experiment this:
We will need:
- PET bottle with the cap, must be transparent,
- a cap of a pen, mine was transparent,
- modeling clay, I used green clay,
- Fill the bottle with water, the bottle must be filled to the brim;
- With the dough make a “belt” on pen’s cap, don’t use too much or the submarine will be very heavy, and drawn;
- Make a small ball with the dough and prick under the lid, This will be your submarine;
- Open the bottle, place inside the submarine, be carfull the cap must stay up,
- Close the bottle,
- Press and release the bottle, slowly and gently, what happens to our submarine?
The plastic is heavier, denser, then the water, but when we put the submarine on the bottle it has a air bubble inside the cap (where we attached the clay ball). This air is compressed when we squeeze the bottle and free some space that is occupied by the water, and the cap/submarine goes down, if we release the bottle the air bubble expands, the water is repelled and the submarine goes up.
Now that you know how to, see what you can do with a bit of training