The Boat/Rock Brainteaser ft Simone Giertz part 2/3

F=ma. a is the same for both (9.8 m/2^2) until they reach terminal velocity.  Which means the heavier ball has more force.  The air resistance gets higher with higher velocity.  So the heavier ball has more force to be able to counteract more air resistance.  "Terminal velocity" is just when the force of the object equals the force of air resistance, so it can't accelerate any further.  Thus, if an object falling has "higher force" (more mass) it will have a higher terminal velocity, assuming equal air resistance potential.  (Which, with two spheres with the same surface, air resistance potential would be the same.)