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I3-14. Magdeburg Hemispheres
Purpose
To demonstrate force arising from the atmosphereic pressure of air.
Equipment
Magdeburg hemisphere apparatus with vacuum pump cart.
Suggestions
Push the hemispheres together and twist while to seat the grease seals. Close the valve and remove the◙vacuum connection before attempting to pull the hemispheres apart.
Images
Description
A mechanical pump is used to evacuate the air from inside a pair of sealed hemispheres. Ropes on the two hemispheres allow two groups of students to attempt to pull the hemispheres apart against the force produced by the atmospheric air pressure. The hemispheres have a diameter of about 5 inches, thus requiring a force of over 250 pounds to separate them when fully evacuated. A safety restraint holds the two hemispheres so that if the pressure releases they will not separate entirely. Three students pulling on each rope may be able to separate the hemispheres.
References
Ernest Hammond, Demonstration of Atmospheric Pressure, TPT 3, 67, (1965).
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See pagesi1. thermal properties of matter
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See pagesi2. transfer of heat
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See pagesi3. gases
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See pagesi4. changes of state
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See pagesi5. laws of thermodynamics
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See pagesi1. thermal properties of matter
-
See pagesi2. transfer of heat
-
See pagesi3. gases
-
See pagesi4. changes of state
-
See pagesi5. laws of thermodynamics
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