Quote Originally Posted by JohnnyEgo View Post
I should clarify that the weight component of friction will mean that the heavier ball experiences more rolling resistance, but the magnitude of this difference will most likely be relatively minor in comparison to the momentum disparity between the two balls. One could do the math on this, but I can't before I have to get my kid to camp.
But he didn't want to use gravity in the original problem, rolling resistance requires gravity to hold the two surfaces together.