Suppose we have this pendulum 1 000 000 km long. if we swing the first ball, the last ball also swing immediately...

>If the strings are attached to the top in increments less than the diameters of the balls,
They aren't, The entire point of a newtons cradle is that all the strings are vertical and there are no horizontal forces on the balls except for the gravitational force caused by their deviation from 0.

0/10

nde-ed.org/EducationResources/HighSchool/Sound/speedinmaterials.htm

nigger, vibration propagation in different material works like sound but at different speed

Dunno about degenerate material tho

>ibration propagation in different material works like sound but at different speed
yes, because in all materials there is a space between atoms.

this is correct