Question

A scientist on Earth drops a hammer and a feather at the same time an astronaut on the moon drops a hammer and a feather.

Which result is expected?

The hammer hits the ground before the feather on both Earth and the moon.
The hammer hits the ground before the feather on Earth, but the feather hits the ground first on the moon.
The hammer and the feather hit the ground together on both Earth and the moon.
The hammer hits the ground before the feather on Earth, and the hammer and feather hit at the same time on the moon.

Answer 1

The hammer hits first on Earth, and they hit together on the Moon.

Explanation: On Earth air resistance slows the feather much more than the hammer, so the hammer reaches the ground first. On the Moon there is essentially no atmosphere, so in free fall both objects accelerate at the same rate (Moon g ≈ 1.62 m/s²) and land together — as seen in Apollo 15 when an astronaut dropped a hammer and feather and they hit simultaneously.