Final answer:
Both a feather and a hammer will hit the moon's surface at the same time due to the absence of atmospheric drag, which results in a uniform acceleration in free-fall.
Step-by-step explanation:
When a feather and a hammer are dropped at the same time on the Moon, they will hit the surface at the same time. This phenomenon occurs because there is no atmosphere on the Moon to create air resistance, which on Earth causes objects like feathers to fall more slowly than heavier objects like hammers. The Apollo 15 astronaut David Scott conducted this experiment on the Moon, confirming that in the absence of air resistance, all objects fall at the same rate regardless of their mass. This outcome is a manifestation of the universality of free-fall under the influence of gravity, as described by Galileo's early theories on acceleration due to gravity.