The speed of a falling object is not affected by its density. In a vacuum, all objects fall at the same rate regardless of their density. This is because the force of gravity is the same for all objects, regardless of their mass or density.

The air resistance that an object experiences can affect its speed of falling, but that is due to the interaction of the object with the air, not its density. In an environment without air resistance, all objects will fall at the same rate.