If you drop a bowling ball, a tennis ball, and a feather from the top of a tall building at the same time, which one will hit the ground first in the absence of air resistance?

All arrive at the same time on the ground.

Explanation:

For this exercise let's use Newton's second law

                F = m a

The force is the attraction of gravity of the Earth on the body

              F = W = mg

Let's replace

             m g = m a

             a = g

We can see that the acceleration of the body is independent of its masses, so that the three bodies, bowling, tennis and pen have the same acceleration and as the three legs of rest. All arrive at the same time on the ground.

this is a good question! i'll do some research and come back when i have the answer!