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Gravity[vector, G] returns a list of SysLoad data objects that apply a force of magnitude mass × G in the direction of vector to the centroid of each body in the current model.
Gravity[vector, G, {bnum1, bnum2, ... }] applies the gravitational force only to the bodies specified by their body numbers.

• The value of mass is taken from the current inertia properties of each body, as specified with the Mass option to Body.
• Gravity accepts the Magnitude option to determine whether the magnitude of the gravitational force is equal to G, or equal to the magnitude of vector times G. The default setting is Magnitude->Absolute.
• After creation, the SysLoad object is passed to SetLoads to alter the state of the current Mech model.
• When Gravity is called without an explicit body number specification, a list load objects is returned corresponding to each body in the current model. If new bodies are added to the model, Gravity must be rerun to reflect the changes.
• See also: Force, Load, Relative.

Further Examples

Load the Modeler2D package and define a simple model.

Here is a SysLoad object that can be used to apply a gravitational force to the centroids of the crank, link, and slider bodies.

The object is really a container for three independent load objects for each body.

Here we apply the gravitational loads to the help model and examine the total reaction forces applied by the constraints supporting the link body.

See HelpModel2D.