Here's why:

* Gravity: The force of gravity acts equally on all objects, regardless of their mass. This means both the 10-pound weight and the 2-pound object will accelerate downwards at the same rate (approximately 9.8 m/s²).

* Air Resistance: In a vacuum, there's no air resistance. Without air resistance, objects of different masses fall at the same rate.

Important Note: If you were to do this experiment in real life, the 10-pound weight might *appear* to hit the ground slightly before the 2-pound weight due to air resistance. Air resistance has a greater effect on lighter objects, slowing them down slightly.