Modify Body - Ground Part

Defines a new or existing part as the ground part.
Examples of where defining a new part may be helpful:
If you merge two models, each of which has its own ground part, after the merge, the resulting ground part may not be what you want so you will need to define another part as the ground part.
You build a model that represents a small subset of your actual system, and then want to expand the model and need to redefine what is ground. For example, if you were modeling a door handle on a car door, you might just have a simple model where the door is ground. Later, you may want to expand the model so that the door swings on the car frame. In that case, you would want to define a new part representing the car body as ground and attach the old ground to the car body with a revolute joint.
 
For the option:
Do the following:
New Ground
Enter a new or existing part to be used as the ground part. Tips on Entering Object Names in Text Boxes.
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