Final answer:
In the absence of air resistance, a feather and a stone fall at the same rate because gravity causes all objects to accelerate at the same rate regardless of their mass. This principle was vividly illustrated by astronaut David R. Scott on the Moon and is a fundamental concept in physics.
Step-by-step explanation:
Ignoring air resistance, a feather and a stone dropped at the same time from the same vertical height above ground level will land on the ground at the same time because they will both fall with the same constant acceleration due to gravity. This is a fundamental aspect of gravity that is not unique to Earth. In fact, this principle was famously demonstrated by astronaut David R.
Scott on the Moon, where there is virtually no atmosphere to provide air resistance, showing that a hammer and a feather fall with the same acceleration. This observation reflects a key idea originally proposed by Galileo: in the absence of air resistance, all objects experience the same acceleration due to gravity, regardless of their mass.
This concept is counterintuitive because, on Earth, we commonly observe lighter objects like feathers falling more slowly than heavier ones due to the significant impact of air resistance on lighter objects. However, in a vacuum or where air resistance can be neglected, such as on the Moon, the feather and the stone (or a hammer, in astronaut Scott's demonstration) would fall at the same rate. This phenomenon is due to gravity acting equally on all masses, giving them the same acceleration towards the center of the Earth or any other celestial body, like the Moon, where the experiment might take place.