Materials Required:
l Newspaper
l Water
l Dinner plate
l Matches
l Wide-mouth jar
The help of one of your parents
Procedure:
- Fold a newspaper page several times until it measures approximately 4 by 5 inches. Soak this piece in water, until it is completely wet, then place it on a dinner plate.
- Fold a smaller piece of dry newspaper, about 4 by 4 inches, into a narrow ½-inch-wide strip. Ask one of your parents to strike a match and light this strip, then drop it into the wide-mouth jar.
- Ask your parent to quickly turn the jar upside down on top of the plate with the wet newspaper. Press firmly on the jar and continue holding this position until the flame has died out and the jar has cooled.
- Now have someone grip the dinner plate and hold it against the tabletop. Try to lift the jar. You can’t—the jar remains fastened to the plate.
This Is What Happens:
The burning strip of paper heats the air inside the jar. This hot air expands and some of it is forced from the jar. As the air remaining in the jar cools, it contracts and its pressure is reduced. The outside air pressing on top of the jar and underneath the plate is stronger than the inside air and holds the two objects together firmly.
