I assume you mean keeping the outer diameter constant and making one ball lighter than the other. That’s clever, it would eliminate aerodynamism as a factor.
However results would still vary, because hollowing out the metal ball increases its buoyancy (see Archimedes’ principle).
They would have the same coefficient of drag, correct, but the air resistance would end up having more effect on the lighter mass of the hollow sphere, so it would be slightly slower to fall.
Archimedes principle here is accounted for in the different weights. Everything that you can put on a scale is already being acted on by Archimedes principle in air.
I assume you mean keeping the outer diameter constant and making one ball lighter than the other. That’s clever, it would eliminate aerodynamism as a factor.
However results would still vary, because hollowing out the metal ball increases its buoyancy (see Archimedes’ principle).
They would have the same coefficient of drag, correct, but the air resistance would end up having more effect on the lighter mass of the hollow sphere, so it would be slightly slower to fall.
Archimedes principle here is accounted for in the different weights. Everything that you can put on a scale is already being acted on by Archimedes principle in air.