1. Siren
Name: Lenka Somorová

2. Needs: tape small plastic bottle scissors beverage cans
inflatable balloon
pliers

3. Procedure: Cans cut off from the upper and bottom.
Cut from the bottom of the bottle.
Over upper edge cans fix the tape membrane of the balloon.
Then to cans insert cutting bottle, so to membrane arching.
Cans glue tape a bottle.
Do a side hole to cans 0,5 cm.

4. Performance:
Blowing to hole in cans. Hear voice siren.

5. Physical explanation:
Between cans and bottle created high pressure .
From the bottle air begins to leak, at this point there is low pressure.
The membrane snaps back to the neck of the bottle. Process is still repeated.