Physics at the University of Virginia
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Al Tobias (wat4y) - Office: Gibson S123 & Physics 218, (434) 924-0538

Physics Demo Manual

Demonstrations are cataloged according to PIRA Bibliography


Due to Physics Building renovations, the lead time to set up demo requests has increased due to the need to transport equipment across campus. Please be kind and let me know well ahead of time what you need.

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 Motion In One Dimension
 Motion In Two Dimensions
 Newton's First Law
 Newton's Second Law
 Newton's Third Law
 Statics Of Rigid Bodies
  video  - Center of Mass of Virginia
  video  - Center of Mass Toys
 Stacking Blocks
  video  - Stability Track
  photos  - Tension in a String
 Rope and Three Students
  photos  - Knot in Static Equilibrium
 Force and Tension
 The Roman Arch
 Rotational Equilibrium
  video  - Giant Yo-Yo
 Applications Of Newton's Laws
 Work and Energy
 Rotational Motion
 Properties of Matter

 video  - Center of Mass of Virginia


To illustrate a technique for finding the center of mass of an irregularly shaped object.


centered image

There are four holes in the map, one of them at the center of mass. Hang the map from each of the outer three holes each time also hanging the plumb bob and marking the plumb line on the map with a piece of chalk. The chalk marks will cross at the fourth hole. Hanging the map from the hole at the center of mass it can be seen to be balanced in any orientation.


  • Plumb Line
  • Stand
  • Map of Virginia