The aim of this science fair project is to understand the effects of compressed air with a simple experiment.
A thick plastic straw.
- Take the straw in both hands and tightly pinch both ends.
- Twist the straw into coils with a motion like pedalling a bicycle. Leave an inch of untwisted straw on each end.
- Ask somebody else to flick a finger hard at the untwisted part of the straw, hitting it with a fingernail.
- The straw will make a loud pop.
As you twist the straw, the air in it gets compressed in a small space in the coils. When your friend flicks a fingernail at the straw, it gets compressed more very rapidly resulting in the walls of the straw bursting.