This is in the league of: Neglecting air resistance, which falls faster: a feather or a brick? The acceleration of an object due to gravity does not depend on the mass: $g=9.8\frac{m}{s^2}$ To find the velocity of a falling object as a function of time you can integrate the acceleration: $v=\int g dt = gt$ Again, no mass involved. The only difference is in the force that is exerted on the objects by the earth according to Newtons second law for gravity: $F=mg$ So the force working on the heavier person is larger, but their acceleration is the same. Is it clear?