Air Show
How? Drop three lit
matches into a glass bottle that has a narrow neck (an apple cider jug works
well). Quickly place a peeled, hard-boiled egg on the mouth of the bottle. What
happens? Why?
1. Why does the egg go into
the bottle?
The
flames heat the air in the bottle. As the heated air expands, some of it
escapes out the bottle. When the matches go out, the air
inside the bottle cools and contracts, thus creating a lower pressure inside
the bottle than outside. The greater pressure outside the bottle forces
the egg into the bottle.
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Turn a glass
of water upside down and the water always falls out. Gravity pulls the water
towards the earth, right? Is there a way to turn the class upside down without
it spilling out?
Why do my ears
POP when I go up in an airplane or dive down to the bottom of the pool?
How? Fill a bottle with
hot water and a bowl with cold water. Let them sit for one minute, then empty
the bottle. Stretch a balloon over the open end of the bottle and immerse the
bottle in the cold water. What happens? Why?
Why Does the Balloon Inflate in the
Bottle?
The warm water heats the bottle which, in turn, heats the air inside the bottle
after the water is poured out. When the bottle is placed in
the cold water, the air inside cools and contracts, causing outside air to be
drawn in, pulling the balloon in and inflating it inside the bottle.