fnorful
Sep 30, 2012, 03:19 PM
A friend wants to make a "Rube Goldberg" contraption involving (among other things) steel balls going down a track (under gravity only, of course!). His concern is whether solid or hollow balls will stay along a track best. He states the multiple energies involved (kinetic, angular, potential) would yield different behaviors for equal-diameter spheres of different weights.
He throws a lot of math references around (which I'm not comfortable with debating); yet my understanding of physics principles is that in "perfect" systems, the mass of an object solely under the influence of gravity does not affect how fast the object falls, nor what distance it may travel if "launched" from a ramp of particular angle. E.g. would a heavy roller-coaster stay closer to the tracks of secondary "whoop-de-doos" than a light roller-coaster?
And secondly, how much of a difference would this make in a real-world (friction-ful) practical application?
He throws a lot of math references around (which I'm not comfortable with debating); yet my understanding of physics principles is that in "perfect" systems, the mass of an object solely under the influence of gravity does not affect how fast the object falls, nor what distance it may travel if "launched" from a ramp of particular angle. E.g. would a heavy roller-coaster stay closer to the tracks of secondary "whoop-de-doos" than a light roller-coaster?
And secondly, how much of a difference would this make in a real-world (friction-ful) practical application?