Question

If a heavy stone and a cotton ball are dropped from a height,which falls with more speed? Who proved this in his experiments from the Tower of Pisa?

Answer 1

The stone would reach a higher speed.

Explanation:

I trust that you know which would fall faster from your own casual observations. (Think of the speed of a leaf falling from a tree.) So who proved this in his experiments from the Tower of Pisa?

I think the question expects the answer to be Galileo. Open this website.
https://en.wikipedia.org/wiki/Galileo%27s_Leaning_Tower_of_Pisa_experiment
You will read that is not clear that Galileo actually did gravity and rate of fall experiments from the Tower of Pisa.

In addition it does not appear to me that even if Galileo did dropp things off the tower, that he did any experiments with a cotton ball. Most accounts of this legend refer the goal being to show that the acceleration due to gravity, in free-fall, is constant. It seems that he used objects of similar shape and density (like a steel ball and a wooden ball), and therefore accelerated at (approximately) the same rate.

But we will assume he did experiment with cotton balls for the sake of this question. The cotton ball would lose the race because it would not be able to push air out of the way as easily as the rock.

I hope this helps,
Steve