Blocks and center of gravity

  1. This is a classic problem shown in many Fundamental Physics textbooks .

    • How do you stack four uniform blocks on top of a table, so that they extend as far right as possible and still remain stable.
    • How should each block be positioned?
    • Can the top block have its entire length beyond the edge of the table?
  • Rules :
So long as the center of gravity is directly above some point whithin area of support,the system will be stable.

    1. You can drag and move blocks horizontal with your mouse.
    2. The stablity of the sub-system is color coded
      1. Green: the system is ins table equilibrium.
      2. Yellow: the center of gravity is right above the edge of the supporting block.
      3. Red: the sub-system is unstable, it will fall in real life.
    3. The center of gravity for each block is shown as a small blue dot.
    4. If you press "Show c.g." button
      1. The center of gravity for the blocks being moved will be shown as a small circle.
      2. The length of the arrow is proportional to the gravitational force for each balanced sub-system.
      3. Label of this button change to "Hide c.g", and you know what it means.
    5. Current mouse position is shown in the "TextField" (relative to top-left edge of the table)
    6. The percentage of top block beyond the edge is shown. There will be a simley when you get 100%!
    7. All the other numbers are coordinates measured from the left edge of the current window and they are all color coded.

    Now can you figure out the physics?
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