* Gravity's Constant Pull: In a vacuum, the only force acting on both objects is gravity. Gravity pulls on all objects with the same acceleration, regardless of their mass or shape. This is why a feather and a bowling ball fall at the same rate in a vacuum.
* No Air Resistance: Air resistance is the force that opposes the motion of objects through the air. In a vacuum, there is no air, so there's no air resistance to slow either the stone or the pencil down.
Therefore, in a vacuum, both the stone and the pencil will fall at the same rate and reach the ground simultaneously.
