Answer :
-- "Free fall" means no forces acting on the object except for gravity.
-- An object dropped through air has two forces on it -- gravity and air resistance.
-- So we're looking for the part of the drop where air resistance is smallest.
-- The force of air resistance depends on the speed through the air, so the
force of air resistance is smallest when velocity downward is smallest.
-- An object dropped through air has two forces on it -- gravity and air resistance.
-- So we're looking for the part of the drop where air resistance is smallest.
-- The force of air resistance depends on the speed through the air, so the
force of air resistance is smallest when velocity downward is smallest.
If there were no air, the object would be in free fall the entire time, and there would be no "terminal velocity". So, the object is closest to being in free fall when the effects of the air are minimized--and that is when the object has the smallest speed relative to the air.
