In a vacuum, what will happen when two objects with different mass are dropped at the same time from the same height?

1 Answer

If there is no air Resistance both will reach the ground at same time.

Explanation:

See the video Apollo astronauts do this test on lunar surface.
Here's the famous footage of the Apollo 15 astronaut that dropped a hammer & feather on the moon to prove Galileo's theory that in the absence of atmosphere, objects will fall at the same rate regardless of mass.

Youn tube video.