Gravitation and air resistance.
There could be some electrostatic or magnetic forces there too, but those would
depend on the composition of the object and the nature of what's floating around
in the environment, so they're not always there. Gravitation and air resistance are
always there.
gravity and drag
The force of gravity will accelerate the falling objects towards itself.
The falling object
Centripetal forces can.
gravity is what makes objects fall
gravity and mass
falling objects.
-- gravity -- air resistance
Two objects falling at the same time will fall with the same speed (assuming they both have similar shape and density)
Air resistance and gravity are the main components.
Mainly gravity, and air resistance.
An unbalanced force will cause acceleration in the direction of the force.