Velocity Vector: Use this tool to give body elements velocities during Run mode. To attach the velocity vector, click on the target body, then drag out the vector in the direction and to the length you desire. The velocity vector appears as a thin red line. You can later change the length and direction of the velocity vector by resizing it, or by setting the strength (i.e., magnitude, in m/s) and direction (degrees) in the vector's Properties Box. You can only attach one velocity vector to any single body.

In the Properties Box, you can also set the label for the velocity vector (default is V) and show (or not show) the vector's label, length (i.e., magnitude), and direction (default is to show only the label).