Its possible to make the block push the ball in this example. Its a nasty workaround though, that will not be much good in a game because it involves moving the sphere relative to the block and 2 updateworlds to ensure the block is stationary when the sphere is moved globally. Collisions are only sphere to something, and if the something is not a sphere then it must be stationary. Hopefully Mark will think about adding some more collision options at some point. Until then the only practical way around it seems to be to write your own.