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= Gravity Coin Well, 1L20.20 =
'''Location:'''

 * [[http://www.physics.wisc.edu/museum/Exhibits-1/Mechanics/GravPit/index_GravPit02-19.html|L.R. Ingersoll Museum of Physics]]

{{attachment:GravityPit-1i.jpg}}

'''Description:''' This demonstration consists of a 56 inch diameter hyperbolic funnel. Coins dropped into this funnel loosely approximate the behavior of matter spiraling into a gravity well - e.g. a black hole.

'''Setup:'''

 1. Make sure there are enough coins in the tray.
 1. Take a coin and drop
 1. Make sure there is not a clog of coins at the bottom of the funnel.

'''Cautions, Warnings, or Safety Concerns:'''

 1. The funnel clogs if too many coins are dropped into the well at once.

'''Demonstration:'''

A mounted coin track is placed on the edge of the  well.  The coins are then sent edge on to roll on the surface of the  well.  Gravity will force the coin to the center of the well and  centrifugal force keeps the coin from falling directly into the well.   As the orbit of the coin continues to decay towards the center the  surface traveled in decreased and the speed of the coin increased.   Finally the coin reaches the bottom or singularity of the well were it  can not escape.  This is designed to show how objects orbit around  massive objects that bend space-time into a well-like structure.  It  also shows gravitational acceleration, orbital decay, and other  classical physics concepts.     .

||<tablewidth="700px"> {{attachment:GravityPit-2i.jpg}} || {{attachment:gravitywell.jpg}} || {{attachment:GravityPit-3i.jpg}} ||


'''References:'''

 * [[http://www.funnelworks.com/|Funnel works]]
 * [[http://en.wikipedia.org/wiki/Gravitational_well|Gravity Well Wiki]]
 * [[http://www.qrg.northwestern.edu/projects/vss/docs/space-environment/3-whats-a-gravity-well.html|Space Envirnment]]

[[Gravity]]

[[Demonstrations]]

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