what has to happen for a feather and a ball to fall at the same rate?
Because the force of gravity is different for both of these objects, they will not fall at the same rate. To make both of these fall at the same rate, we need both to have the same mass so that the gravitational pull is equivalent also.
They will NOT fall at the same late.
A ball will fall much faster than a feather. A feather tends to float down, much as a ball, it immediately drops.