The velocity can be applied as displacement over a time increment of some seconds. For example, if you want to apply 10 m/sec velocity you should apply 0.01m , over a time increment of 0.001 seconds (0.01/0.001=10 m/sec). Also, a two-step solution is required. That is:
End Time=0.001 sec
Automatic Time Stepping=Off Substeps= 1 (or more for more accurate results)
End Time=0.002 sec
Automatic Time Stepping=On
Substeps: Initial=30, Minimum=10, Maximum=100 (The values are random. You could specify the ones most proper to your problem)
Then you can apply the Displacement (0.01 m) as you can see from the picture below, and you should deactivate it on Step 2. To assign the Displacement to the whole body just mark the whole body and pick Apply in the Geometry tab under the Details of the “Displacement”.
Also, you cannot apply velocity, displacement etc. in point masses.