Grade Level: Kindergarten to 2nd grade; Type: Physics
Demonstrate the relationship between the amount of stuff and the amount of pressure in a closed system.
Because the rubber glove is stretched tightly around the rim of the jar not allowing anything - including air - to get in or out, the glove-in-the-jar is a closed system. The jar is completely filled with the glove and air. What happens when you try to put your hand into the glove in the jar?
- One glass jar large enough to put your hand into (a big maraschino cherry jar from a bar works well)
- One thick rubber glove (like the ones for washing dishes)
- Put your hand into the glove. How does it fit?
- Take off the glove and hang it into the jar with the fingers pointing down.
- Stretch and fold the wrist-edge of the glove over and around the rim of the jar.
- Now try to put your hand into the glove. How does it fit? it’s difficult because there’s no room left; the jar is already full! If you really try you can do it, but it’s hard – you feel a lot of pressure. You have to squish the air in the jar to make room for your hand.
Terms/Concepts: Closed System, Pressure