Nicholas86, Thaks for thereply. I think I understand the physics panels of the particles but for now I just want to simulate (fake) particles hitting a ball or cube and reacting (bouncing off). If I can accomplish this, then I can hopefully extrapolate to other things. The key is I don't want it to be static. If it were to be static it is not as much of a problem becuase I could change the floor position, but with an animation, it's not the same. Here's a screen shot. Also the Effects and Surface fidelity are set to HIGH and the directional force strength is set to 1000.