In addition to joints and springs, you can affect the behavior of a certain solid by applying an external force or torque on it.
The Force/Torque group is located at the rightmost on the Links menu. You find the following two buttons in this groups, as shown in the following image:
Force: This button allows you to apply an influence (push or pull) which tends to change the motion of an object including to begin moving from a state of rest, i.e. to accelerate. In other words, a force can cause an object with mass to change its velocity. A force has both magnitude and direction.
Torque: This button allows you to apply an influence which produces changes in rotational speed of an object.
The Properties Panel of the Force/Torque appears at the left-side of the screen. Properties that are intersect by Force and Torque, as shown in the following image:
Name: Where the user specifies a name for the new force or torque.
Mode: This section allows the user to interchange between force and torque modes.
Application Space: The user specifies whether the force or torque will follow the affected solid as it moves (Local), or stay static on the original point of application (World).
Affected Solid: Where the user selects the affected solid.
Location: Where the user selects the application point and axis for force or torque, in addition to that the ability to flip the force or torque direction.
Magnitude Function: This edit button, if clicked, displays the Function Editor dialog box where the user specifies and selects the desired magnitude function for force or torque.
The Force/Torque Function Editor dialog box appears, when you click over the edit button of the Magnitude Function. This dialog box is shared by both of Force and Torque, it contains the following parameters:
Function Plot: Start, End, Step, Plot Area, and Update button.
The Function Editor dialog box of Magnitude Function for Force and Torque is the same Function Editor dialog box of Motor Function for Prismatic and Revolute Joints.
