Allo! :-)

I'm working on a game where an arm, at the end of which is a cylinder, rotates at an angle (the pivot being at the end of the arm without the cylinder), sweeping along a rotating platform, in an attempt to knock other cylinders (prize pucks) off of the platform (which is also a cylinder :P). The pucks are at rest on the platform, until they are collided with, at which point they glide just enough to get out of the way of whatever they are colliding with. Also, since the platform is rotating, they too are rotating in world space. The arm is at rest, not attached to the platform but just over it, so it is still except for when the player is bringing it out toward the edge, or it is returning back to the center.

For now, I'm just having the arm rotate around in a fixed circle, knocking at pucks in its path, just to get the collision set up. I am a complete newb to physics, so *please* be gentle in your answer.. but.. How do I set it up so that the arm is not affected by the pucks, but the pucks are affected by the arm and each other? I want the arm to be unveering in its path, but the pucks to make way for the arm and each other.

Please help.. :P My grade is at stake.

Thank you in advance,
Stonerunner