Monday, 16 June 2014 14:58

## F1-15: PRESSURE GLOBE

• ID Code: F1-15
• Purpose: To illustrate several interesting phenomena related to air pressure
• Description: This is a glass sphere into which a balloon can be inserted to demonstrate effects of air pressure. The sphere can be sealed with a rubber stopper. Three ways to use the Pressure Globe:

(1) Place a balloon into the lipped opening of the Pressure Globe. After stretching the mouth of the balloon over the lip, blow into the balloon until it conforms to the bottle's interior surface. Insert the stopper in the bottom hole while retaining the pressure inside the balloon. Once the stopper has been firmly inserted, remove your mouth from the balloon. Observe that the balloon does not deflate.

(2) Place the balloon into the lipped opening of the Pressure Globe and place the stopper in the bottom hole. After stretching the balloon over the lip, have a student blow into the balloon. Air cannot be blown in. Discuss why not.

(3) Prepare the Pressure Globe following the procedure in Step 1. Once the balloon has been fully inflated and the stopper placed in the bottom hole, pour approximately 100 ml of water into the balloon. With the large opening facing upward, place the Pressure Globe over a sink. Now remove the stopper. Observe what happens. Discuss what force causes the water to squirt out of the bottle.

Note: Care must be taken to insert the rubber stopper far enough that it fully seals, but not so far that it cannot be grasped to be removed.

• Availability: Available
• #### F1-01 FLUID PRESSURE VS. DEPTH

Demonstrates that fluid pressure increases linearly with depth and is isotropic. Read More
• #### F1-02: FLUID PRESSURE VS DEPTH - ANEROID GAUGE

Show water pressure versus depth with an aneroid gauge. Read More
• #### F1-03: PASCAL'S VASES

Show water pressure versus depth with an aneroid gauge. Read More
• #### F1-04: EQUILIBRIUM TUBES

Demonstrate that pressure is transmitted equally throughout a fluid. Read More
• #### F1-05: DOES WATER SEEK ITS OWN LEVEL?

A trick to challenge the students. Read More
• #### F1-06 WATER SEEKS ITS OWN LEVEL

Demonstrate that pressure is dependent only on depth, and not on the shape of the container. Read More
• #### F1-11: HYDRAULIC PRESS

Demonstrate dramatically Pascal's Law and the large forces attainable using hydraulic systems. Read More
• #### F1-12: PASCAL'S LAW - COILED TUBE PARADOX

Illustrate Pascal's law in a dramatic way. Read More
• #### F1-13: CONSTANT WATER PRESSURE

Demonstrate a mechanism which produces a constant water pressure. Read More
• #### F1-14: PISTON DIAMETER VS TRAVEL - WORKING MODEL

Show that with an incompressible fluid the bigger piston moves more slowly than the smaller piston. Read More
• #### F1-15: PRESSURE GLOBE

Demonstrate principles of air pressure. Read More
• #### F1-21: LIPLESS STRAW

Demonstrate the role of atmospheric pressure in the operation of a drinking straw. Read More
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