Heisenberg Uncertainty Principle
If we were to apply this to a steel ball of mass .002 kg +/- .00002 kg, rolling at a speed of 2 m/s +/- .02 m/s, the uncertainty in momentum would be 4 x 10-7 kg*m/s .
From the H.U.P, then, the best we could be sure of the position of the steel ball would be: ?x = 5.3 x 10-35 J*s / 4 x 10-7 kg*m/s