Conservation of energy and momentum governs Newton cradle. If $n$ balls were lifted, $n$ balls will bounce of on the other side. This happens if all balls have the same mass. Now, assume that you have a cradle with balls $a,b,c,d,e,f.$ All balls except $f$ has weight 1. Ball $f$ has mass $n+0.5$ (1.5 or 2.5). We lift ball $f$ and bring it to motion. What will happen on the other side?
I would guess that n balls would fly to the original height and one more ball will fly half way.
As far as I can tell physicists never tried this experiment fearing it will destroy the Universe. :-)
The so called duplicate is NOT a duplicate because it talks about integer mass ratios, whereas I ask about fractional mass ratios. Also, that answer provides a link to a single clip about a single case. that doesn't answer anything. Besides, even if that question was related, there is no way for me to revitaliate it.