The heavy one because mass times force is equal to speed. The lighter one has less mass to it goes faster without as much effort. I hope that helps!
Umm...Well...
Heisenberg's Uncertainty Principle says that we can never know both the position and rate of change of a particle at any time. We can only know one or the other. This leads to rather silly jokes that deal with uncertainty, probability, and superposition. So, saying that "Heisenberg may have slept here" is essentially saying that it is uncertain if Heisenberg slept there or not, making for a rather silly, but slightly unfunny physics joke.
I am pretty sure it is 4.002602
