I have a simulation of two blocks racing.  You can input the initial position, initial velocity and acceleration of each object and see how their motions compare to each other.  I would like to add ghost traces that would leave a ghost image of each object's position at some set time interval (every 0.1 time unit or something).  And I am at a loss to figure out how to do this.

I attached my file if anyone wants to take a look.

Thanks in advance for any help.