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Deletions are marked like this. Additions are marked like this.
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 * '''Bay:''' [:MechanicsCabinetBayB3:(B3)]  * '''Bay:''' [:MechanicsCabinetBayB5:(B5)]
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 attachment:mainPhoto  attachment:mainPhoto.jpg
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Insert succinct description of demonstration. A weighted wood block is placed on an inclined plane with opposing tension provided through an attached string. The tension is just enough to balance the weight so that the force due to static friction is just enough to prevent slipping. A nudge then triggers the block to slide.
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 * ''''' '''''  * N/A
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 1. List steps for setup then procedure.
 1. ...		  1. Place the inclined plane on table near a corner closest to the audience so the they can see the protractor.
 1. Choose an appropriate angle setting, and lock the plane into place with the set screw.
 1. Choose one of the two wood blocks (brass bottom or wood bottom) to use and add weight if desired.
 1. Choose the appropriate amount of counter weight to use and attach it to the block via the string.
 1. Place the block on the inclined plane and run the string over the pulley with the weight hook hanging freely.
 1. Help the system to stabilize if needed. If the weights were chosen correctly, the block should remain at rest.
 1. To demonstrate how changing the coefficients of friction affects the system, the same procedure can be applied to the opposite block. To take away the difference in weights between the two blocks, a different, appropriately chosen weight combination and angle must be used.
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 *  * This demonstration may require practice and some minor calculations beforehand.
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Friction arises from electromagnetic forces at the microscopic scale. It acts to oppose motion. Its magnitude is F_fr = μ*F_n = μ * m * g * cos( It's a good idea to start with a lower angle using the wood bottomed block since it is less heavy and has a higher coefficient of friction. Assuming this ordering is used, the following steps can demonstrate the difference in coefficients
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Discuss the physics behind the demonstration, explaining some of the various steps of the demonstration when appropriate.
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||attachment: photo||attachment: photo||attachment: photo||attachment: photo|| ||attachment:IncPlaneWeights02-250.jpg||attachment:IncPlane01-250.jpg||attachment:Weights01-250.jpg||attachment:Weights02-250.jpg||
||attachment:WoodBlock03-250.jpg||attachment:WoodBlock05-250.jpg||attachment:WoodBlock06-250.jpg||attachment:WoodBlock07-250.jpg||
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 * List any references
  * [http://en.wikipedia.org/wiki/Friction Friction - Wikipedia]

[:PiraScheme#Mechanics: Table of Mechanics Demonstration]

[:MEEquipmentList: List of Mechanics Equipment & Supplies]

[:Demonstrations:Lecture Demonstrations]

Friction on an Adjustable Inclined Plane, 1K20.36

Topic and Concept:

Location:

  • Cabinet: [:MechanicsCabinet:Mechanic (ME)]

  • Bay: [:MechanicsCabinetBayB5:(B5)]

  • Shelf: #1 attachment:mainPhoto.jpg

Abstract:

A weighted wood block is placed on an inclined plane with opposing tension provided through an attached string. The tension is just enough to balance the weight so that the force due to static friction is just enough to prevent slipping. A nudge then triggers the block to slide.

Equipment

Location

ID Number

Adjustable Inclined Plane

ME, Bay B5, Shelf #1

Wood Blocks with Attached String

ME, Bay B5, Shelf #1

Weights with Weight Hanger

ME, Bay A1, Shelf #4

Important Setup Notes:

  • N/A

Setup and Procedure:

  1. Place the inclined plane on table near a corner closest to the audience so the they can see the protractor.
  2. Choose an appropriate angle setting, and lock the plane into place with the set screw.
  3. Choose one of the two wood blocks (brass bottom or wood bottom) to use and add weight if desired.
  4. Choose the appropriate amount of counter weight to use and attach it to the block via the string.
  5. Place the block on the inclined plane and run the string over the pulley with the weight hook hanging freely.
  6. Help the system to stabilize if needed. If the weights were chosen correctly, the block should remain at rest.
  7. To demonstrate how changing the coefficients of friction affects the system, the same procedure can be applied to the opposite block. To take away the difference in weights between the two blocks, a different, appropriately chosen weight combination and angle must be used.

Cautions, Warnings, or Safety Concerns:

  • This demonstration may require practice and some minor calculations beforehand.

Discussion: Friction arises from electromagnetic forces at the microscopic scale. It acts to oppose motion. Its magnitude is F_fr = μ*F_n = μ * m * g * cos( It's a good idea to start with a lower angle using the wood bottomed block since it is less heavy and has a higher coefficient of friction. Assuming this ordering is used, the following steps can demonstrate the difference in coefficients

attachment:IncPlaneWeights02-250.jpg

attachment:IncPlane01-250.jpg

attachment:Weights01-250.jpg

attachment:Weights02-250.jpg

attachment:WoodBlock03-250.jpg

attachment:WoodBlock05-250.jpg

attachment:WoodBlock06-250.jpg

attachment:WoodBlock07-250.jpg

Videos:

References:

[:Instructional:Home]

fw: Friction_on_an_Adjustable_Inclined_Plane (last edited 2013-07-12 18:18:14 by localhost)