Our prediction
In everyday life, a hammer reaches the ground first. Air pushes much more effectively against the broad, light feather.
Remove that air, however, and both objects experience the same gravitational acceleration. Their masses differ, but the rate at which gravity accelerates them does not.
What TRI LAB needs
This is being shaped as a future TRI LAB experiment. The lab version will need a visible vacuum chamber, a clear prediction before the drop, and a comparison between air and vacuum.
What we want to learn
The useful lesson is not simply that “they land together.” It is that observations change when we isolate a variable—in this case, air resistance.