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## NetLogo User Community Models

 Download If clicking does not initiate a download, try right clicking or control clicking and choosing "Save" or "Download".(The run link is disabled for this model because it was made in a version prior to NetLogo 6.0, which NetLogo Web requires.)

## WHAT IS IT?
This is a project that lets you explore the concept of Center of Mass.

## HOW IT WORKS
You start of with a system of mass. The system is divided into two sides with a divider in the middle. The left and right sides are green and blue respectively and are divided into little squares representing mass. In the center of the system is a white dot that represents the location of the Center of Mass of the entire system. As one eliminates blocks, the center of mass changes.

## HOW TO USE IT
You can eliminate blocks in one of three ways:
1. You can eliminate blocks randomly from each side simultaneously.
2. You can eliminate blocks from one side or the other randomly.
3. You can eliminate blocks from a specific location by clicking that location with the mouse.

## THINGS TO NOTICE
Notice how the center of mass changes as you eliminate blocks. Does it move into the boundary of existing Mass? Does it moved into the empty space vacated by the mass?

## THINGS TO TRY
Can you use this model to predict where the center of mass will end up? Can you eliminate mass to make the Center of Mass move to a specific location?

## CREDITS AND REFERENCES
Thanks to James Newell for his original model and thanks to Pratim Sengupta for his contributions to making this model work.

Porter, D.A., and Easterling, K.E., Phase Transformations in Metals and Alloys, 2nd ed., Chapman & Hall, 1992

Shewmon, P.G., Diffusion in solids, 2nd ed., TMS, 1989

## HOW TO CITE
If you mention this model in an academic publication, we ask that you include these citations for the model itself and for the NetLogo software:
- Wilensky, U. (2007). NetLogo Solid Diffusion model. http://ccl.northwestern.edu/netlogo/models/SolidDiffusion. Center for Connected Learning and Computer-Based Modeling, Northwestern University, Evanston, IL.
- Wilensky, U. (1999). NetLogo. http://ccl.northwestern.edu/netlogo/. Center for Connected Learning and Computer-Based Modeling, Northwestern University, Evanston, IL.

In other publications, please use: